USF Air Support Center felt REALLY overshadowed by Infantry/Mech
I disagree. The call ins were very powerful, cheap, and came out quickly when you had fully upgraded them (the upgrades were actually quite a bit cheaper than the infantry/mech support center upgrades iirc.
I made a post elsewhere but the double P47 strafe for 40 muni (upgraded) basically instakills MGs if they don't immediately move, double P47 bombing run for 60 muni levels any house and destroys defensive positions.
Enemy can counter P47 bombing run with AA but the strafe is much harder and almost guarantees a decrew on any heavy teamweapon as long as it comes from the shortest distance.
It's definitely hard to beat the 76mm shermans, but with air support helping to dislodge enemy teamweapons and protect points, it's definitely not way overshadowed.