Two important points about shields that you might not know:
In order to damage a shield, you need penetration equal to or higher than the shield’s resistance. This means only Reflective shields can stop beams with 24 pen, like the Federation Fusion beam (which, IMO, makes this particular weapon way too good - at least the Proton beam sucks aside from it’s boosted penetration). Beams with 24 penetration will go straight through High Recharge and basic Cruiser shields. This is less a problem and more a confusion issue - logic says you’d need to exceed the target’s resistance, not equal it.
Only your highest-resistance shield matters when calculating penetration. So by all means, load up on Multiphasic shield generators - it’s not like they’re actually costing you anything as long as you add a single Reflective shield generator! This makes no sense to me considering how damage is normally apportioned (being divided into four clumps that hit random shields). A strike from a weapon that can penetrate some of the target’s shields, but not all of them, should be able to damage the target’s low-resistance shields rather than being shrugged off completely by the single high-resistance generator.
I’ve actually suspected these for a while, but finally did some empirical testing today to be sure. The former is slightly unintuitive, and the latter takes away a lot of the potential complexity from shield selection.
This also seems as good a time as any to comment on how crappy the low-resistance shields are - or perhaps how strong beams are! I honestly can’t imagine building a Cruiser without a max-resistance shield generator right now, because any ship that’s vulnerable to beam lasers is going to get horribly mutilated by beams due to their range (the biggest weakness of Frigates is that they cannot resist beam lasers). The boost in shield strength and recharge for playing with lower resistance shields needs to be much, much higher for them to be even worth considering (beyond their cheesy current role of backing up a reflective shield).