Some other factors to consider. I think across nov and Dec, if Nintendo could put 3m on shelves, they would probably sell all and win both month's. However I have my doubts they can manage this, and I'm thinking sales will be 700-800k max. Not enough to win.
The pro accounts for roughly 20% of ps4 sales, but I think in order for Xbox to be a contender, I'm thinking the X needs to be close to 50% from here on out. I'm not sure it can really sustain that.
So my thinking is a close Xbox>Ps4>Switch November. Ps4>Switch/Xbox December. If Nintendo manages a first for them in keeping up with stock, then no doubt they would be top instead.