You could probably add one fire shrimp and that's it for cleaner shrimps.
maybe 1 or two camel shrimp if you're into those. Mine disappear, I had one I thought died reappear 3 months later.
Doubt harlequin is consitured but for clearifaction 1 pair per tank..
One pistol shrimp would do fine in there with anything as well.
Any other type of shrimp like sexy, anemone, and bubblebee, you can add until you can't see through the glass (although camels may be a little nasty to them)
Coral banded shrimp should be the only shrimp in the tank if you plan on those.. they're too aggressive sometimes even for fish if underfed.