The problem with your account is this - where were the “friendly” Libyan security guards? The account sounds to me like one created for plausible deniability with a pre-arranged scapegoat who either will have conveniently died in the attack or will be killed while resisting arrest. If you have to ask why the Libyan government would do this, you’d have to ask why Muslims simultaneously say 9/11 was a Bush plot and a great victory for Islam. For a fair number of Muslims, logical contradictions are just part of the fun.
Most of the security guards stayed with the consulate personnel to the safe house and then exfiltrated after that location was burned down.
There are a number of wounded Libyan security guards that suffered gunshot wounds. I’m guessing that only one was a turncoat.