I would be more concerned with the 4 clowns in the same tank than if they will host it or not. Not all clowns will host a nem, some will host corals or even powerheads. lol
Also, like metioned above, the tank does seem new. Nems require an established tank, preferably over 9 months old, pristine water and super lighting......
180g- Mostly BIG fish and some coral. ~80g Nuvo- My coral tank with "happy fish"~ 90g- FOWLR Not the not happy type of fish~ 125g- Freshwater Malawi Cichlids ~10g- Nuvo- The refugees from the Ich of '18