I have 6 tangs in my 180, the only battle I had was when I added my lieutenant tang tang. My orange shoulder was less than pleased with my decision to ad him. They are all getting along fine now after a week or so of an all out brawl.
6 tangs huh? Cool.
I've got 4 in my 180.
Lieu
Regal
Unicorn
Scopas
4 would work in a 220.
I have 3 in my 187g, a blue, a hybrid yellow scopas and a powder brown, along with a foxface and they get along great. My tank is very open though. Once I find one for the right price I will be adding a black tang, this will be my final fish. I think you will be more than fine.