Part of the problem with charts like this is that it still would be best to have expert interpretation of the data with respect to keeping snakes: It's still only a comparison of domestic rodents+, not the natural diet of snakes, and what's more, I think many of us might assume that a slightly higher % of protein in adult rats makes them "better than" mice for snakes, BUT we still don't know if that higher % is what's actually best for the snakes- many times, nutrition is about a certain optimal balance of nutrients- ie. how they work together in the body. So I think we should be careful about making assumptions.
For snakes that accept some variety, I think that's a good idea too. Going back many years, when I bred & sold rodents, I did often feed more variety, but since then I've had very healthy & long-lived snakes despite feeding only mice. Which is why I lose no sleep over it.And remember that wild snakes evolved without optimal conditions too- if anything, they're designed to handle "adversity".