You have to show me a replay where a scout car can push 4-5 squads and survive. Pushing 1-2 squads I am fine with it because it requires micro and risk for "unexpected elements" such as fast Puma or other squads coming from distance, not to mention limiting micro for capping.
The underlying point is, OKW player has it easy with a free truck pushing with kubel and sturm combo to outright win through clutch play.
A scout car can't but a M5 can. And you shouldn't be able to push 1-2 squads with an M3 either because it makes no sense as a game mechanic, and can entirely negate enemy infantry for very low cost.
Why should a scout car be able to kill pgrens because it can just push them around despite pgrens being a perfect anti-armor counter? Not to mention how easy it is to kill a gren squad before they fire their faust, or after they do.