Why did Megatron allow Starscream to live so long? Update:Optimus had a trash squad

[Neuromancer]

I'm watching this Megatron keeps making stupid mistakes. like not attacking the autobots when optimus prime was dying.

 

[Neuromancer]

Starscream always been a shiesty muthafukka. Just like optimus prime stays getting his ass kicked

I think that was more on his squad who he had to save all the time than himself.