But gareth, remember that OOP in Jet mode was enough to carry Rattrap, Cheetor, and Silverbolt on him, and he still had room.
I apologize in advance, I don't know how to shrink images apparently.
But I agree that Dragon Megs shouldn't be that big. I'll have to rewatch Master Blaster to take a look at the size comparison between Megatron and Optimus.
My Recommendations:
Megatron:
*I would make Dragon Megs slightly bigger than Tigerhawk/Rampage.
*Increase the other Megatrons slightly, as to make him more on par with Rampage.
Optimus:
*I'd take OOP down a notch too, TM Megs was roughly half the size of OOP, and was staring only slightly up at Prime's spark when OOP had it. BUT, he should still be the biggest hunk-a-junk around.
Others:
*I'd make Inferno taller. He should, in my opinion, come up to Ori/TM Megatron's chin/neck.
Other than that, I think you're dead on with the sizes. Nice job!