If anything I think strength (and other attribute) based characters should have more ways to permanently raise a stat, maybe like the mirror that can give +2 have some kind of blood magic that can drain a stat for another to raise it beyond 20�. Maybe even at a terrible conversion, like 2-3 points lost to raise a stat by 1.
Either way there shouldn�t be an easy way for a character to have more strength than a character built around strength. But I don�t expect this to change.