Solve the issue by rolling back all units, and give fair warning that whatever you don't use won't be worth crap in the next cycle. So here are the realistic options:

1) roll back units for one cycle
2) reimburse each player for every tank in their inventory
3) give each player 250 of whatever the highest cash unit will be

Do not reimburse every player blindly some amount of cash or gold, since people will create bluestack accounts and farm money. But if factions are locked, you will see less players trying to game the system. Sure, some two man team may try to create 58 other accounts but will be tough to pull off.