adding more chromis to tank is it too much?

So I was wondering if I could add 2 more blue green chromis. So far I have a snowflake moray 2 pj cardinals, 2 ocerillas clowns and a foxface, 1 blue green chromis. If I added 1 or 2 more chromis would it be too much bio load I also wanted to add a tang. Would the new chromis if similar size to the one small one I had for a few days be a problem with him and is this too much bio load with the tang. The tank is well established and is around a 100 gallons with around 90 lbs of live rock and a very deep sand bed like 4-6 inches. Keep in mind I do not have a sump.