If he was truly stubborn then he would be more likely to fit what players he has available to the same system.
I get the impression a lot of people on here think you can just change systems and styles of play at the drop of a beat. You need some consistency of tactics and systems or players will be all over the place.
This season we’ve played the following formations, off the top of my head:
5-3-2
5-2-1-2 (AM behind 2 strikers)
5-2-2-1 (the box)
3-6-1 / 5-4-1 (whatever you’d call it)
4-2-3-1
4-1-2-1-2
If anything, Robins has been comparatively changed things a bit too often.