Shaking my head wondering what is wrong with the tried and true china drive? Williams used it on their Chuggington and Brewster / Thomas locos which they had a fire sale for $59.99 & they use it on all of their locos, at one time there was a lifetime warranty.
I know it's not the favorite for 2 railers, but it is a bullet proof drive. And Lionel wouldn't need to add all of those weights because the actual trucks and flywheels would provide enough weight.