ON a side note, I should mention something from the Demolishers fluff
"The number of crew in a Demolisher varies. Sometimes there is a Commander, a driver, two Gunners (what), two Loaders, and one Communications/Engineer man. ~~~ The number of crew members depends on when the tank was produced."
Personally I always fluff 5 or 6, Commander, Driver, Gunner, Loader, Loader, and maybe Assistant Driver. MG variants get 2 extra crew to work the pd weapons.