I really like this racial ability
I used to read it and go, “Meh, 2% extra secondary stats from gear, whatever.”
But I was getting into the real math of it, and it plays out well when coupled with the 10% penalty for going over 30% in a secondary stat. The Human Spirit basically allows humans to ignore that “diminishing return” penalty on secondary stats up to 37%.
And that plays out with the human tribe so well! Ever since the first Warcraft game, humans have constructed their townhalls with big ol’ grande clocks prominently featured. Humans gain reputation faster than other races. Humans are all about banking, commerce, interest, etc. So to have their racial be something like "I banked this much of my secondary stat, to pay for the “diminishing returns” on it later, I think that’s just great.
Awesome design all around!