I expected this to be resolved in the latest patch, but it doesn't seem to be. When I stack a unit with 2 movement and one with 1 movement, it still asks me how I want to use my second move, even when it's evident that I can't make it. I don't know if this is intentional (so you're still on this stack and can optionally move the unit with remaining points), but I find it irritating as hell, because I wouldn't stack two units if I didn't want them to stay in the same location.