It would also be about the worst monsters of all in D&D: Wizards.I don't think the OP was about bone devils. it was about people, like alchemists and healers and bandits and stuff.
Do you want to deal with a full wizard stat block for every one of those buggers? I sure don't.
Edit: Also, there's no alchemists in 5e. You just... can't build them like a PC unless they're a rich PC that buys all their alchemy from the lack of crafting rules.