Alright, time to clear some things up:
-They're preview figures, and will thus only give a SMALL glimpse at the line, without revealing any gimmicks (although Screamer's gun looks like his gunhands on the movie proto).
-These are cometformers. They use comet-esque forms, dropships if you will, to enter a planet.
-These are NOT movie-accurate. For one we won't see Starscream in prototype mode. Second, Prime only appears as a shadowy figure. Third, it was described much differently in the script. In it, they arrive with the help of more normal-looking comets, which then open as flowers to let the Transformer step out before attaching again and reconfiguring itself into the altmode parts the Transformer needs for it's disguise. In other words, they're a bit like reversed protoforms/stasispods.