I think “clean up crew” is overrated, and in many cases is another way this hobby creates for us to spend our money.
We spend money to “replenish” our stocks of CUC when they die off (starve), just to have the new batch slowly starve off, adding more nutrients to the tank.
Sure, if you have a problem like bubble algae, get some emerald crabs; hair algae get some turbos or sea hare; aiptasia peppermints etc. But otherwise, I don’t think a tank needs to have the typical “cleanup crew” besides the ones that usually show up on their own (amphipods, bristleworms, etc).