My personal experience is different I see +3 on melee and ranged skill often and +4 on stamina and bravery. Though I do get +1 from time to time (had 3 +1s to melee skill in a row on a swordmaster for example. It is not a bug really, just a design decision, which I can live with, though I would personally prefer a bit more distinction in stats between a peasant and a swordmaster, who should be a legendary fighter.)
