It’s ironic when reading this since I suggested this very thing back in March(link → DarkHelmet’s Mercenary idea and you replied with the following:
No, this is too much. I would be ok with this for offline play but not for online.
Keep in mind that when I suggested it that 2.4 had not yet released and wouldn’t for another month. I should probably go through and massively update this at some point when 2.5 and the next Ladder comes rolling in. Anyways, it seems your position has shifted modestly to allow it for Online but only for solo play. I for one wouldn’t mind having more capable Mercenaries since there is always Classic Diablo for those aching for a REAL challenge since Mercenaries are an afterthought due to how weak they are. Furthermore, you can simply not have a Mercenary if you find them to be too OP. Nerfing their stats/damage based on number of players is not the way to go since what’s the point in having them if you do that? To act as fodder like on Classic Diablo? Waste of Gold if you ask me as I’d be better off Gambling than hiring Mercenaries.
Adding Glove, Belt and Boot slots to Mercenaries would instantly make any item that rolls Ethereal not entirely useless. I also advocated for Jewelry(Rings + Amulet) but I can compromise on limiting it just to gear with durability(Bows/Crossbows not withstanding).