Ok, so now would be a great time to add an undo zone feature. For example, I move a large group of units, we'll call them A. Then I move large group B somewhere else, then large group C. I later decide I want to change what I'm doing with group A. Current choices to undo them are to right click and undo each individual unit in A, or to undo the whole turn and have to remove B and C that I've already done. Both are a PITA.
So a 3rd option, like right clicking in a land or sea zone and being able to "undo all units moved into this zone" would be awesome.