With the current fishes,that I have in my 4 by 2 by 2 community tank which is Dory-2 inches, black tang-3 inches,blue tang-4 inches and yellow tang-3 inches, is it possible for me to add 3 more yellow tangs,1 naso tang and 1 archilles tang? Will it be too congested? How will the current yellow tang react when i introduce 3 new yellow tang? Is there any way or method I could apply to prevent my current yellow tang from bullying the newly introduce fishes? Please advise.. .