Martials don't even get anything from a 5th level multiclass into another martial class
(ttrpg.network)
Ironically he hates playing it because of all the extra rules, but loves creating characters because of all the extra rules. Writing that out I think I just realized if I take out BAB progression and replace it with proficiency bonuses and have multi attack rules just be 5e rules I think all his issues would evaporate.