You don’t. The rules make sure the characters are roughly on the same playing field but that’s about it. This is not a competitive game where everything has to be balanced. One player being overpowerd should not be your concern. A player being underpowered and feeling like they can’t to anything is much more of a problem and if that happens allow the player in question to respec or create a new character (at least if the concerns are valid and it does not happen every two weeks or so).