I like the pattern of this color wheel. It looks interesting and geometric.

Burnt Sienna only neutralizes blue, not yellow or red. I realize you were trying to keep it simple and not go into too much depth on color theory. But if you're looking for a color that will neutralize ANY color, you'd be better off with a Neutral Tint. Each brand makes their paint with a different formulation, but they make it so it will neutralize any color. I used M. Graham's Neutral Tint instead of Burnt Sienna.
I enjoyed playing with the mixes with the Buff Titanium though. I've had a tube for a while now, but hadn't played with it much.

Just for fun I did a wheel with a Primary and Secondary palette using neutralizing pairs. I know this wasn't part of this class, and I do already have some knowledge of color theory that I used to choose these pigments. But it was a fun experiment and I thought I'd share. The colors in the center were mixed by adding it's complement.