I get the fact that you really don't like Mollberg as the starter, but you keep citing this body of work business. My hypothetical has a pretty valid point of concern, i.e. competition level. How does Portland State's defense compare to Montana? Montana State?
Let's add in the fact that this is still a new offense and the offensive line has been a sieve for the majority of the season. The coaches seem to think that Bartels would have done worse than Mollberg in all those games, so who's to say they weren't right? Against Portland State he was 7 of 8 and had lead the longest UND offensive drive of the year to that point. There's no evidence to show that he wouldn't have been able to keep up that kind of performance throughout the game had he stayed healthy.
I agree with other posters saying that Mollberg needs to trim down. When he was brought in, I was expecting an athletic, dual-threat capable quarterback but haven't really seen any of that from him.