I'd say 15/21 (or maybe 18/18 for more shielder build), because you can spent points into shield and/or PT, so it gives you more flexibility(eg. against shooters). It's good for light-medium armor, because it's fast and with a lot of wpf, so you can go 1h|shield+throw or even 2h+shield|dagger+throw.
But if want be medium-heavy infantryman it's better to have more strenght imho and specialize in one weapon.