well that's 2 or 3 braincells less to operate a JT or Ele, I can agree on that.
BTW if you stun a vehicle, e.g. with a tulip rocker or a pak stun shot, the vehicle can't use its cannons as well and damaged engine and crit engine are completely different things. Crit engine is what you get when you crew an abandon vehicle.
Add a ISU to that. Or did you forget the times all soviet players spammed ISU’s and put them in the middle of the map and went afk for dinner? Axis had no ISS cannons to combo it with some dumb Ram. They were just told to go around and flank it. A 3 braincell reaction just like the amount needed to activate the ISS cannons or operate a ISU.