KV-2 is a bit too slow for an anti grimm tank in my view. When I said 'barely mobile' I meant in comparison to the average hunter on foot. If you want to compare it to a real world tank, better comparisons would be the [AMX 13/90](http://www.panzerbaer.de/types/pix/f_lkpz_amx_13_90mm_tunesien-001.jpg) or [M551 Sheridan](http://www.military-today.com/tanks/m551_sheridan.jpg) light tanks.

EDIT: That said, a KV-2 is fine too.