So a long time ago, in a galaxy far away, the constructicons were on Tatooine and scanned a rancor...hmm........
You may be on to something... though this is Lucasfilms largest cgi. kinda explains why he doesn't really stand up...
It's possible that at some point in the movie, he'll rear up on his hind legs like the Rancor I guess George said it was cool since he and Spielberg are good friends, and Stephen is the Producer.
So Dev is going to get something rammed in his mouth keeping it wedged open while Optimus can slam some huge door down on his head.
That's why Mudflap gets sucked into the Grinder Vortex. Devs can't consume the ugly bot, and so is incapacitated while Optimus comes in with a huge-ass sledgehammer and starts beating the hell out of the combiner. Mudflap would die, but who likes him anyway?
I dont follow this so their both big and focus on having big mouths... I dont see a link one thing a did notice is that Long Haul and Rampage seemed to have swapped sides