Why not simply give that perk “+1 for all stats for every levelup the char has” and not only at levelup so it would be dynamic AND you would not have to pick it up on the first level up, if you don´t want to at this point. This way the perk would always scale and still usefull if picked up later
"I am a Paladin!"
>OMG, Malthus, there are no damn paladins in Battle Brothers...<
"OK, OK! Then I´m a wrecked down minstrel drunkard pretending to be a paladin, singing so wrong in the midst of battle that even the undead run in fear... Better?!"