OK. I have played the 12th campaign twice, once with Marcus for my knight and once with Hakim. The traitor was the same both times - Thordal.
Does that answer your question?
Sorry but no, I mean if you play like you said first the campaign with marcus and see who the traitor is and in this case thordal. And then play Thordal on the same campaign and see if it still he that is the traitor.
But thank you for playing so you could answer the question thank you so much.
I have a poor memory, and its been a while but after my previous post I think I played with Thordal as my knight every mission, starting from the first mission that he was available. And then Elias was the traitor.