Rollout (Japanese: ころがる Roll) is a damage-dealing Rock-type move introduced in Generation II. It was TM04 in Generation II.
As Air Commander of the Decepticon attack forces and arguably one of their most lethal warriors, Starscream sees himself as a hero on the wrong side. Over the centuries he's come to believe both Optimus and Megatron have lost sight of what is best for the Cybertronian race, and simply pursue their own agendas. Even though he has been loyal to the latter, he disagreed with Megatron's obsession with the AllSpark and decided that, for the greater good of their species, a new leader should emerge.
If his attitude toward his fellow Decepticons is inconsistent, his attitude toward the Autobots is not: Kill them all. Barricade might not be as large as most of his peers, but he is every bit as deadly
Megatron tends to become so obsessed with the object of his desires that he can ignore "secondary" matters, glaring flaws in his plans. Otherwise, he likely wouldn't have chased after the AllSpark alone, and spent centuries entombed in the Arctic.