I’ve begun silently fighting back against jerks on the subway who sit as spread out as possible. Basically I match your stance.
This guy was sitting on the train with his knees splayed and his hands on the seat to either side of him. So I slowly backed up into the seat next to him forcing him to either move his hand or have me sit on it. Then I spread my knees equally wide and stuck my elbows out just as far.
It’s amazing how uncomfortable this makes men.
Eventually he closed his knees more (so I closed mine.) The ladies across from me noticed this silent warfare and were slightly confused. When he finally got off the train and I sat like a “lady” they realized what I did and grinned at me.