Sorry, but this is a false equivalency, at best. You're comparing the use of an ability (ram) to a static unit (mine). Let's look at the 'counter-play' order.
Mine:
#1. Place mine
#2. Opponent could detect/destroy mine
#3. Mine detonates or is disabled
Ram:
#1. Click Ram
#2. Ram can't be stopped once clicked
#3. Ram hits
Again, every single (balanced) unit and ability in the game follows this pattern, because it's good game design.
Assuming that the T-34 is always in range is exactly the same as assuming the mine is already in place, and both require counterplay (screening).
Both are also vulnerable to zoning out the necessary support units.
Mine:
1. Mine is laid down in position.
2. Mine can be either spotted in being laid, or detected by likely singular sweeper-equipped engineer squad on the enemy team.
3. If enemy player fails to detect mine, enemy player suffers. Otherwise, Ostheer player loses munitions for nothing.
Ram:
1. Produce and position T-34/76
2. T-34/76 can be zoned out or destroyed by screening units (and not singular upgraded engineer squads)
3. If enemy player has failed to do this, enemy player suffers. Otherwise, Soviet player loses T-34 for nothing.
I'm really not quite sure how one can say one thing is balanced and not the other, particularly if, as I have suggested, the ram ability is moved to vet 1.