If Sigmar survives I think his help will come in handy during the 5th Ordeal. I have a vague memory of the 5th Ordeal being faction based, also. Might be wrong, but once death becomes a permanent risk then having another (relative) powerhouse is very beneficial.
Maybe they will encounter digestors in each ordeal after the safe mode. It's because of that, that the progression of the story will be quicker than before. Just a thought.