Starscream believed in the strength of one bot over another. That's how you were respected. That's how you earned your authority. It's how Megatron took lead in the first place.

Clearly, after the fight that he had years ago which set who was stronger than who between the two, he had not changed one bit.

And here you were, challenging his authority as second in command as a puny minibot working some low rank job on the ship. And when you pounce him, he gladly accepts the fight.

He gets a few good hits in, punches landing on your faceplate, before you take advantage over him, slamming him into the ground below you and pinning him there. A wave of familiarity goes through him, and he smirks.