Do not like the idea of bounding to background more than it is already now. Battle characters have their boost from the start. +10 in melee skill for sellsword means 4-10 level ups! Almost half. And there are other bonuses too. Sellswords are way better than tailors already. Even +1 for every roll for them will make their advantage huge. Give farmhands a chance, not every sellsword was born a sellsword, matbe some of them were apprentices or fishers in early days, so why neglect modest backgrounds.