If Gearbox ever reworks Dominance I hope they just add a basic damage multiplier to it that has 11 levels of bonuses, depending on your Mayhem Level. Mayhem 0: +50% multiplicative damage for the pet (active all the time). Mayhem 10: +550% multiplicative damage bonus (again, always on). That way, with then 2 multiplicative damage bonuses for the pet (afaik The Power Inside is multiplicative as well) the pets damage and damage bonuses would massively profit off each other and be more potent the higher the Mayhem Level goes.
Sure, this would make Dominance an even worse Clusterfuck to code, but who cares? It would fix the skill, would fix the pets for pet-centric builds and all Fl4k players in the world would absolutely love it.