Seems like there are two main issues people bring up:
1. Heavy vehicles/Call-ins come in too early and dominate games.
2. Losing initial engagement is too punishing due to distances to objectives.
Regarding #1, I think fuel and CP income should be scaled to size of teams. Something like:
Income = -1/6 * Team Size + 7/6
So for 1v1: Income = -1/6 * 1 + 7/6 = 1 (or 100%)
2v2: Income = .83 (or 83%)
3v3: Income = .67 (or 67%)
4v4: Income = .50 (or 50%)
Lengthens early game, delays heavy tanks and call-ins. All without having to impact 1v1 balance at all.
Regarding #2, the maps are just not well designed mostly, and need to be fixed. Relic has explicitly said they're working on that.
I'm sorry to disappoint you, but that would make Axis factions even stronger.
Till the time any allied tank will hit the field, wehrmacht and okw will have won the game already. They can utilize Manpower and munitions better than the allied factions, especially the OKW. Till the time your first t34 comes out I will have already vet 4 volks running around with shrecks or endless mines on the field.
Sure you'd never see Heavy tanks, but they are not really needed for winning.
Imagine a time window in which Obersoldaten can freely melt infantry without fearing a sherman because you raketenwerfer and volksshrecks have just taken a sherman out.
The game is won by better tactics and micro. Heavy tanks just don't penalize mistakes that much.
On low level 3on3 4on4 people have bad micro and tactics, therefore the deciding factor sometimes seems the heavy tank.