Starscream's expression sours further; Megatron has clearly struck a sore spot. "No," he grinds out, "I am a loyal science officer."

Was this universe's Starscream the second-in-command of the Decepticons? Because it sure sounds like it. Was his obviously terrible relationship with Megatron a result of that? Is that some kind of inevitability?

Pfft. No. Absolutely not. Clearly this Megatron never had the same bond that Starscream does. Which is why he adds, more or less unwisely, "And his conjunx socia."

See, Megatron!! He's important. He has what you didn't have. Everything Is Just Fine.