Most of the complaints so far are about 1v2 and 2v3 games. Unfortunately with lower player counts there is not much that can be done about that. If the teams end up unbalanced like 1v3 or 2v4 etc, you can type !swap or !rtc to swap from the the larger team to the smaller. No mod privileges required to do so.
Also regarding balance, keep in mind that some tanks may seem overpowered but they all have weaknesses. While the ezekiel stealth tank can destroy mammoth tanks 1v1 (use these to take out mammoths), the much cheaper amx-13 can demolish the Ezekiel with ease. The secret is to circle around it. The Ezekiel doesn't have a rotatable turret and the vehicle itself turns relatively slowly. The infrared stealth tank on the other hand will take out the amx-13 very quickly, but will be no match for main battle tanks like the m1a2/3, Pendekar, Mammoth tanks, or Titans,