Personally I think they had to have killed pa bos soilders to capture scribes, but others that know mid west bos say no. So with Ceaser not going into detail we really have no idea how they were able to capture scribes.
If cl tangled big time with mid west bos we would know it I would hope.
The whole scribe thing isn't really of much importance to me, but some Legionnaires have had a run-in with a Paladin/s... and prevailed.
Then again maybe they wouldn't leave Nellis, still one hell of a tought net to crack. Numbers would be irrelevent against their artillery.