the hangar flaks aren't bad and if you plan accordingly, they can easily cover some gauses or even a starbase. what I try to do when I have them is to make sure the battle takes place at the hangars. so I give my fighters a local well order and make sure my other ships don't stray around (depends on the situation of course if that makes sense). that way, the enemy fighters keep taking flak dmg and my own will be able to pwn them.
also, don't forget that the vasari version also has a defense against squads. think it stuns them or phases them out somehow. never been able to see it actively though, so I'm not sure if it is any good.
maybe advent could use some defense upgrade against squads, but I find their currents boosts, synergy and shield bonus, pretty useful as is.