That's what I keep thinking too, which is why I ultimately land on no.I don't follow Patriots beat writers very closely and didn't realize this was a Curran obsession.
I think all the questions in the second paragraph are apt and important. My gut instinct is that this would be much easier to pull off with a 80/20 type split, where Cam was the starter and Mac offered a strategic change of pace. That still hews fairly closely to everybody's understanding of how a football team works. A 50/50 split or a situation where either guy could end up with more snaps based on game flow seems like too big a stretch.
If they're going to do it, I think they should go all-in with it or don't even bother. Going all-in would probably mean a level of QB micromanagement that I'm not sure anyone in the building would be comfortable with. I'm talking subbing the QB out basically the same as any other position, based on packages and situations. That may actually be the most optimal or efficient use of their resources, given the differing strengths of Cam vs. Mac, but that's the kind of thing that is easy to do on a spreadsheet or a video game, but not as easy to actually pull off in real life without making sacrifices elsewhere.
If it became simply "giving Mac a drive or two as a change of pace" then I'm not quite sure what the point would be. Just start the clock on Mac or don't. Otherwise I don't think they'd be doing either of them any favors. Either go all-in with being weird at QB, or simply pick the guy who they feel gives them the best chance to win overall. Splitting the difference with some kind of half-measure doesn't make a lot of sense to me. Seems like that would be a path towards a lot of the same downside risks, without much of the potential upside.