If you're gonna be that nitpicky then none of them are the right size, as they should all be the exact same height except Swoop who should be a bit shorter. Instead they are different sizes. Grimlock and Slag are taller than Sludge who is taller than Snarl (personally I would prefer it if Sludge was the tallest, but it's whatever). The Fanstoys dinobots exaggerate the attributes of the characters from the cartoon. Swoop's defining attribute is that he is the flyer of the group. It doesn't make thematic sense for him to have a bodybuilder physique like the others.