I’ve just noticed this, does anyone else have this problem?
Yep. I tried getting my fighters to escort a squadron of bombers in a recent battle but the game wouldn’t let me pick them as a target. Fighter squadrons seem to be an invalid target for those orders. Might be because the order needs a single specific ship and aquadrons are treated as a group entity?
Tried setting squardron size to 1, still no dice.
yeah and it would be useful imho, doesnt work for me either
plzclifffix? 
It might have been intentionally left out because it seems like it would be a major pain in the warpdrive to implement.
It might be easier now that we have the Stick Together order that keeps fighter squadrons together, more like a single target. Since (as I understand it) there is a single “leader” in the squadron, maybe the Escort/Formation orders could lock onto the squad’s current leader. Would only work in conjunction with the Stick Together order though. Or maybe not at all (I leave that up to Cliff to decide).
I hope you’re right. I’m going to test it in a few minutes, but it it doesn’t work, PLEASE make it an option to escort or be in a formation with other fighters. PLZ!!
EDIT: Doesn’t work. 
god damn it!
it would take some fiddling and require new, larger fixed formations for it to work. it is entirely intenstionally blocked by the UI because it probably works out pretty messily if you managed to get it to work.
I admit it would be very desirable to have mixed fighter/bomber squadrons, I’m aware of the need for it, it’s just not succesfully implemented.
i think you can do one of the options … retaliate against ships attacking target or some such.
Getting fighter squadrons to protect other squadrons is a must, via the escort orders this could increase bomber survivability.