[This 'bias' is silly and he his now doing his Primely best to ignore it.]

I wouldn't know. I simply believe Megatronus does not want those with his own mark under the command of others, but it is impossible to know for sure without asking him yourself.

[Rather like the 'real' Megatron...]

His bias, whatever the source, is the sort of incident we would like to avoid in the future.