“It’s probably Matt Mercer’s fault.”
Wanting something hard coded is fair enough, however I feel this is a well-solved problem in RPGs. In a skill based, points based system if a character has invested points in survival skills they don’t have those points available to spend on savoir faire. Similarly, if they have spent lots of points on strength, combat skills, and so on they won’t have points to spend on mental stats and knowledge skills etc.
The only trick is balancing the costs of these in the system and making sure the game requires them in play a commensurate amount.
I was imagining something deeper than skills. Like, resistance to magic or the ability to sense motives. Stuff that can’t really be learned as a skill.
But maybe the skills you pick* determine where you are on the Savagery/Civilized spectrum?
*Except for the fact that I prefer skill-less RPGs now. But it could be traits or whatever.