That's a good article, but I don't draw the same conclusion as you did.
Yeasts (and some bacteria) are in fact facultative anaerobes so with oxygen available they produce 18x as much energy from a sugar molecule as without oxygen. That's a high hurdle to beat.
If #2 is the primary factor, then a stir would have to provide all the organisms in the starter access to far more new sugar molecules than it provided the facultative anaerobes access to new oxygen molecules.
Hard to predict in theory, there are so many factors in play. Would be easy to test if had a sealed CO2 or N2 filled chamber to work with.