It really depends on the species and at what stage of it's life. I find many to do quite poorly in smaller tanks, Clown gobies included. Mostly the small younger ones which feed quite a bit on pods
and such. As they age and become accustom to tank life they tend to do better. There are TR
available if you can find them that would be better suited.
A newly aquired goby placed in a small tank right away will waste quite quickly unless it adapts to prepared or you feed live foods. Every attempt I have made about 50%+ end up being transfered to a larger tank (or returned) due to a sunken belly.