I tried to have a clown harem , it didn’t work for me, had 5 clowns in 40b maybe not enough? Two pairs and one loner clown that got ate by a tube anemone. Eventually the two pairs started fighting over my biggest BTA (have 10) so I sold one pair and just left with two clowns lol
See my build thread, but be forewarned that in addition to the Fire Clown and couple of BTAs there are also 15 rock 'nems, 4 sexy shrimp, a bunch of Florida Ricordea, and a ton of tiny gobies. But the Fire Clown and Green BTAs are the "showpieces".