Some quick thoughts

Adding upkeep reduction for marauders to "despiser of humans" (norsca and mixus tabletop lords trait) for example. These are lord specific traits I believe so it can be a decent amount (-15 or 20% maybe). The reasoning here being this trait is one of very few that has a negative effect (which I would argue might be good for all traits to have negative aspects, but that is another discussion), so the benefits should outweigh the other similar traits, and currently they do not, also the paying them less thing fits with that theme.

That one was bit messy but I had some reasons I guess, another example in clearer form;

Tough; Armour +50, Melee defence +8, Wounded reduction time -4, enemy agent success chance -20%
(the armour buffs for lords/heroes are in general just sad, and tough should grant the highest number, unlike with strong...)

Strong; Armour +10, Weapon strength +20%, Melee attack +8, Speed +15% and/or Charge Bonus +20%.
I think the armour bonus here could be removed/replaced (if possible as I know base game trait edits are not so easy to remove effects for) as the intent of the trait seems to be to indicate above average muscle strength)