I’d say 3 yellow better than 2. Ime yellows get along with each other pretty well. Introduce together tho for sure.Also I would say only 1 yellow for the same reasons. In general the rule of 1 tang per body shape seems to be a good rule of thumb. The Naso gets huge, so have a plan for when they are too big for your system. The Naso's I just saw in Maui were easily 2 feet long. The yellow tangs were 10" dinner plates too.
I would get the 9 anthias and one of each tang. I love seeing them swim so actively. And I had 2 of them turn male in my tank, it was weird seeing a fish that I knew I didn't buy like that.
I like blenny's too, consider lawnmower blennies for algae control, and a fish that can cameflouge somewhat into the rockscape. I also like my Midas Blenny for a rock laying swimmer.