With antifighter frigates, the orders I use depends on the opposition I expect to face. If I’m facing something that I think my main combat ships can clear out before it can hurt my antifighter frigates too badly, I might just let the antifighter frigates fly off the leash, with ‘engage fighters 100%’ at a range that is reasonable for the weapons that I gave the frigate (if I’m using Antifighter Missiles, I go for the maximum range on the missile), and I might leave the ‘engage frigates’ and ‘engage cruisers’ orders on, albeit at low percentages (not more than 20%, probably more like 10%), to try to control the exposure of my antifighter frigates to enemy frigates and cruisers. In this situation I will probably also put ‘keep moving’ orders on the antifighter frigates. Other orders (like last stand, vulture, or retailiate) depend on whether or not I feel adding them will improve antifighter performance for subsequent attempts on the challenge or battle.
If I expect more serious opposition (large groups of rocket fighters, or significant frigate or cruiser forces), I usually use escort orders (when I think enemy fighters will arrive first, and thus cause my antifighter frigates to stop and allow my heavier frigates or my cruiser line to pass through the frigate screen before they take too much fire from the enemy fleet), or, less frequently, I use formation orders (to keep the antifighter frigates behind something that I expect to be a more tempting target for enemy frigates and cruisers). Alternatively, since destroying enemy frigates and cruisers is more likely to win me the battle than destroying enemy fighters, I might arrange the formation or escort orders so that several antifighter frigates absorb the first several volleys from the opposing fleet, thus costing me ships that I may not care as much about as, for instance, a torpedo platform.
Escort orders will normally keep frigates mostly ahead of the ship that is being escorted, while formation orders allow you to mostly control the relative position of several (or all) ships in your fleet. Formation orders can be too restrictive, though - on occasion I’ve made mistakes where I chose a formation that resulted in half my fleet stopping out of range of the enemy the lead ship chose to target, or where the ships I wanted them shooting at were inside the minimum range and they couldn’t do anything about it because the tank I chose for my fleet’s centerpiece isn’t dying anytime soon. As a result, I prefer to design my ships to have roughly the same speed as one another and leash particularly fast vessels (usually intended to operate in the cruiser line for antifighter duty) to a couple ships I expect to draw fighter attacks by means of an escort order. I tend to set escort ranges at roughly 300-400 range, though I don’t have any real reason for doing so.
If you right-click on an order, it removes it from the order list for the selected ship(s) (this can also be done by left-clicking the order as if you were going to modify the priority, range, or other settings, and clicking the ‘delete order’ button). If you remove an 'Attack ’ order from a particular ship or set of ships, these ships will ignore any ship type for which there is no active attack order in favor of closing to the set engagement range of an enemy vessel of one of the remaining ship types (to a lesser extent, this behavior holds true even when you leave all attack orders active on a ship, but greatly increase the priority of one target type over one or both of the others, but the driver AI selects targets based on proximity and priority, not just priority - a frigate at range 100 is a more tempting target even at 1% priority than a fighter at range 10,000 with 100% priority, and this may or may not be behavior acceptable for your fleet plans). Note that the vessel will still select enemies for which it does not have attack orders as valid targets for its gunners if no enemy for which the vessel has attack orders is in weapons range, and if all surviving enemy ships are of a type that your ship has no attack orders for, it will select one of the surviving enemy ships as a driving target (though I don’t know what the default engagement range values are in this case - which is one reason why I prefer to leave all attack orders active on my antifighter vessels, so that I can keep them at a relatively safe distance from ships intended for antiship duties).
An antifighter frigate that moves at 0.2-0.3 speed when your cruiser formation moves at 0.15-0.2 speed isn’t likely to get too far ahead of the main body after the ship it was supposed to escort dies, and if its highest priority targets (or the only ship type for which it has attack orders) are fighters, it should head for the closest enemy fighters. If that happens to mean flying into the concentrated fire of the enemy cruiser group, unfortunately there isn’t any way to prevent that (unless you have the Direct Control option enabled and don’t have difficulties with instability, since this allows you to change some of the orders on your ships during battles). Still, if enemy fighters are leashed to enemy cruisers or frigates, you’re probably better off using your own fighters to clear out the enemy fighters, or ignoring the existence of fighters and use the money you would have spent on fighter defense for cruiser-killers (and perhaps frigate-killers, but cruiser-killers often do well enough at the frigate-killer role).
One thing you might consider is combining the EMP frigate and the Antifighter frigate designs you have, assuming you either are not facing very large fighter forces or are willing to spring for the extra frigates. That way, you can give the frigates high-priority ‘Attack Cruiser’ or ‘Attack Frigate’ orders with a sufficiently high engagement range that your antifighter weapons will usually be unable to shoot the cruisers or frigates and the EMP missiles will occasionally or usually be in range. This works slightly better for antifighter frigates armed with frigate pulse lasers and tractor beams than for those armed with antifighter missiles, though, as it’s easier to keep the frigate in EMP range but out of pulse laser range than in EMP range and out of antifighter missile range. However, it does compromise the frigate’s antifighter capabilities, and using frigate pulse lasers instead of antifighter missiles compromises the frigate’s ability to defend multiple ships, so it depends on your needs. Plus, with higher priority on killing cruisers, the frigate may not be in position to engage enemy fighters. This can work well with escort orders, though - ships under escort orders will stop moving when they are within the specified engagement range in their attack orders unless it would cause them to violate their escort orders, which means that an antifighter frigate with ‘Engage Cruisers 100% at 800 range’ will stop when an enemy cruiser is within 800 range and not closer than 400 range, and as long as fighters are the next-highest priority target any antifighter missiles on the frigate will prefer to target fighters that are within firing range as long as no enemy cruisers close to within 550 range (or whatever the maximum is for antifighter missiles - I think 550 is the right range, but I’m not sure), but will also not remain further from the target of the escort order than the range specified when you gave the ship the order.
My general notes for antifighter frigates:
If you expect there to be large numbers of rocket fighters, getting the average armor on the frigate to above 12.0 is more important than having an extra shield generator, though I’d still prefer to have at least one shield generator than having only slightly more than 12 armor, and if for some reason I cannot get the armor above 12 but can carry two or more shield generators, I’ll try a different frigate hull or put two or three shield generators on the frigate. Alternatively, leave slots empty and deploy lots of the frigates - but fighter rockets rapidly destroy unarmored or lightly armored frigates.
Frigate tractor beams are great for antifighter frigates, whether you’re relying on Antifighter Missiles or Frigate Pulse Lasers or Ion Cannons, or on the guns of nearby cruisers, for killing fighters. I would sooner have 1 antifighter missile and 1 tractor beam than 2 antifighter missiles, though I wouldn’t put more than two tractor beams on a given frigate (and I’d usually only put one tractor beam per frigate, because there aren’t many frigates with more than five hardpoints, and one tractor beam is plenty for four antifighter missiles).
If the enemy fighter force doesn’t include rocket fighters, a single shield generator with resistance greater than 8 is a sufficient defensive investment for the frigates, unless enemy frigates and cruisers are set to prioritize frigate destruction. But if that’s the case, your frigates won’t live long anyways. The smaller the frigate, the less likely fighters are to slip beneath the shield bubble, which means your antifighter frigates can in some cases outlast cruisers when attacked by fighters, even if you don’t put a single armor plate on the frigate but load the cruiser up.
If you have four or five hardpoints available for antifighter weapons, consider using two antifighter missiles, a tractor beam, and a Frigate Pulse Laser, with any fifth weapon module left to your discretion.
If there are significant enemy cruiser or frigate forces on the battlefield, keep the antifighter frigates close to (or behind) a larger frigate or cruiser, preferably one which has better defenses than the antifighter frigates, since the larger ship tends to attract more fire (note that if enemies are prioritizing frigates, a large frigate is better for protecting your antifighter frigate than a cruiser is, unless the cruiser can kill any enemy ships that come close quickly enough to prevent your antifighter frigate from being badly damaged, disabled, or destroyed - this may be the case when the threat is enemy frigates, but it’s unlikely if the threat is enemy cruisers).
Protection is a two-way street - the antifighter frigates likely cannot deal with heavy warships, be they frigates or cruisers, and your own heavy warships aren’t that good at dealing with fighters, but they can probably take a lot more punishment than the frigate can. Alternatively, if the antifighter frigates are more of a luxury than a necessity in the particular battle, switch the roles around - have the heavy frigate be the small ship, and let the antifighter frigate be a big target. While the antifighter frigate draws enemy fire, your heavy frigate can blast away at whatever is shooting the antifighter frigate in relative safety.
- Several minimally armored and shielded, cheap antifighter frigates have a decent chance of providing better fighter defense than do a smaller number of heavily armored and shielded antifighter frigates, especially if the enemy fighters are set to prioritize cruisers or your own fighters over frigates. Just keep something nearby to take the fire from heavy weapons for the antifighter frigates. If the enemy fleet is focusing on your cruisers and doesn’t bring many rocket fighters to clear out frigates, but does bring enough laser, pulse laser, painter, or torpedo fighters to justify dedicated antifighter platforms, going for the cheapest shield that can resist fighter lasers may be a better idea than going for the best frigate shield. Just keep it behind the cruiser line and close enough to hit strafing fighter groups (this an example of a situation where formation orders work better than escort orders - escorts tend to get out in front of the ships they escort unless they are for some reason slower than the ship they escort, while ships in formation tend to lag behind their set position relative to the leader).
Edit: sorry for the huge wall of text. I hadn’t previously realized how much I’d written.