You think so? Then try it. When you do it for the first time, just by description on how to do it its almost impossible. I would say that learning how to properly micro a sniper is easier. There is a reason why most players don't even know you can crush on purpose - they never happened to see that happening in lower skill games.
Lol. Dude I know how to crush. I find it easy with a p4 let alone a Cromwell. With the Cromwell in general the movement is much smoother. And the crushing much more deadly.
It literally takes no further skill than clicking to the side of the tank the infantry you want to crush are. Just keep clicking tight pathing arcs. Infantry get magnetized to the rotating tank and can't move except to get further crushed or to retreat which, as I mention above, is a lame solution.
But hey, I'm not against crushing entirely. As I've also previously said, I think it should do health damage and rarely kill a model and should be normalized across factions. Cromwell and m10 were simply ludicrous.