Open order units and Monstrous units get a free 90 degree turn at the end of their movement if they don’t march. But a 90 degree wheel never takes 100% of your M characteristic, unless the unit is extremely wide, so it seems like it would make more sense to march pretty much always. If something prevents you from marching, that’s another story, but when you have the choice, when would you ever choose not to? What am I missing?