If it eases your mind that same clutch was used on motorcycles with near twice the Hp of an M20 so it is more than good enough
It was used on the pre-war B series as well and there it was 1 set of plates shorter because the B's were "medium weight sports" bikes where as the M clutch was supposed to be able to haul a 1/2 ton of sidecar + load .
Post WW II nothing odd to see one with 2 x 44 gallon drums of oil or a 1/2 ton of coal in a commercial box sidecar .
