Coh3 noon seeking assistance in getting better

Casual player here. Have been playing co-op against expert AI with friends and i dont feel like i am getting better. Playing US with airborne, i feel like my options against an AI that has double resources feel kinda limited. Particularly the transition from early game to mid game with the other side having armour quickly.

Any suggestions on how to improve against expert AI? Or should i try British for the straightforward tech tree?