[Executor]

Trust me when I say rollbacks are the work of devil and only use one if the very game is at stake. I've personally been in 3 games that were shut down by roll back bugs.

All sort of **** starts to happen if anyone sends in the same turn or doesn't delete that turn before downloading the rollback turn. Commanders turning into units, units becoming commanders, items disappearing, etc.
It's too much of a risk and generally it's only done if it's a game breaking event.
Ask around.