Just a mad idea I'm throwing out there. What if you could exchange infantry/vehicle/aircraft resources? The exchange rate would be quite severe, so say 500 aircraft resources gets you 100 infantry resources etc. The point is for people who partake in only one or two of the three types of combat but struggle to keep up with the resources required. The game seems to been designed assuming you will want to play infantry, drive tanks and fly vehicles, but if you want to be mainly infantry it's hard keeping stocked up, especially if you want C4 for your LA, or BBs/proximity mines for your Inf, or AT mines for your engie, or indeed all of those. Do dedicated pilots and tank drivers have this problem too?
I'd use basically all my air resources for tank mines. This has been suggested before, but I still definitely agree with it.