OKW-only suffers a lot to artillery. Mixed axis with one Ostheer to support and do the dirty, unrewarding work (build caches, reinforcement bunkers/halftrack, Stuka Bombing Run on stationary artillery etc.) makes it really difficult for any set-up of Allies to deal with late game elite infantry and super heavy tanks from OKW.
One Ostheer player in the mix that knows what he is doing will deny the very important stationary artillery that the allies have and at the same time he will massively decrease the fuel penalty to his OKW team mates. Coordinated SU/USA teams do have ways to deal with it or at least find other options on how to counter what's on the field but at the same time I understand why it must be really difficult for the Allies if two random teams are paired up in automatch.
It's not helping either that a lot of the team maps are rewarding camping which benefits the Axis team the most.
I agree. some VPs are in very defensible locations, so if Axis are able to lock it down, it becomes a nightmare for Allies. At least the Axis can [ump out heavy tanks to break the stalemate