I have had plus do have these fish.
Well I had a yellow watchman and he was a neat fish picked out a cave that was facing the front of the tank so I could almost always see him. However he was afraid of almost everything, especially cleaner shrimp. Well I guess I only had him about a month and one day he was breathing heavy on just one side of his gills. I think he must have darted and hit a rock or something.
Died in the next couple days.
I have a
yellow clown goby now.
I chose this fish mainly because my tank is small and he is small and because I had orange and purple fish already. This fish is pretty tiny. The last fish I added to my tank. Luckily no aggretion was shown and the little guy is doing fine. He has almost no fear of anyone and is ignored by all his tankmates.
I like the clown goby because he doesn't hide he out front and center all the time but the watchman was really fun to watch.
So I guess depending on tank size and any hazards could play a role in the clown doing well.
HTH somewhat
my experiences
good luck