I thus think that an argument and a means exist to remedy each of the above:
1. Allowing Infantry Tech to either go above 2, or give them anti-tank capability. Remove motorization as an applicable tech to infantry (give the fully motorized US/UK armies an extra move point, only allow the Axis/Russians to have their dedicated motorized inf. units, which was historical), allow A-T up to a certain level. Hubert added those 2 attacks to tanks early on in SC2, but with no countering boost to infantry.
2. Already discussed implementing limits on operational movement. Since there is already precedent in limiting amphibious units, would seem like a natural to me.
For #1, I'm not sure there is anything to fix. That's just the way the game is balanced, I think it works well. Get those tanks together for some blitzkrieg!
For #2, it might be too big of a change for this iteration of the game. Operating is the super-power that holds Germany together. If you tone it down you'd have to toss them a bone or two either in unit limit and/or income.
I'd like a system where there's logistic slots that could be spent each turn, let's say 3 (For Germany) plus logistic tech. Operating air or HQ would take 3 slots, tanks and armies 2 slots, Corps and lower 1 slot. But to compensate operating would be free of charge. Over a couple of turn it would be still possible to mass troops but not in the fire brigade way it is now.