How big are the tang and the clowns? If they are medium size I would say that you are probably getting close to capacity.

In my 75 (90 gross) I have

2 false percula clowns (1 small, 1 tiny)
2 green chromis
1 royal gramma (pretty fat and big)
1 blue tang (small)

I am considering added a lawnmower blennie soon and mandarin next spring.

I think that will be about it for me.