koski

Yes but even when you disable Auto Leveling, you cannot change companion stats like Constittution, Perception or Might
 
Those stats are really critical to how the characters play, their defences, etc
The stats in this game are what you're born with. They are not reborn when you recruit them so its natural you will not get to choose their stats.
 
Should be noted that the companions have not had that bad stats since 1.03. They should be doable for most builds you can come up with their given classes.