When in the game lobby, try changing the player bonus field, which now represents different gameplay modes. Some of them include a human allies option.
I couldn't quite understand, but here is my response.
Skills, perks, and artifacts not giving bonuses is due to map scripts not being activated.
If this is a campaign, I assume that it's probably a bad installation problem. Did you install the mod on top of ToE 3.1?
I would also advise you to read the FAQ
Dear translators, please check this point.
Later, I'll look into the leadership skill for the necromancer.
Added 10 minutes later