You're correct in that the increase in momentum of the rotating mass due to a heavier tire may well be the larger force acting on the brakes with larger tires, but it's not the only one. If the "unsprung weight" between two sets of running gear is equal, but the diameter of one set is larger than the other, the larger diameter set will cause the brakes to work harder, due to the longer moment arm. "Just sayin".......

Randy