Made the Wrong Choice? Please help...

[lizb]

Hi everyone, I am trying so hard to keep my boys happy and healthy. Please tell me what I'm doing wrong. I've mentioned before that my trio was declanning. Christopher (dominant/aggressive) attacked Digger Luke was minding his own business. Digger is in a separate 10 gallon with very minor injuries, as I intervened before it went on too long. I anticipated the breakup of the group, so I got two "pups", who turned out to be just slightly over pup age, Apollo and Vulcan. I had planned to try to split the "pups" with Digger. However, literally HOURS after I moved Digger, Christopher started showing signs of aggression toward Luke, chasing, arched back while standing side by side, etc. 
So, 5 gerbils. 3 tanks. 1 aggressor.

Since I moved Digger only hours ago, can I switch him back with Luke and put Christopher on his own? I'm not trying to punish anyone, just keep as many boys safe/happy as possible. Any insights would be appreciated. Thanks!

[ella]

I'm not an expert in the least, but may I suggest putting Christopher on his own in the ten gallon and one "pup" paired with each other gerbil? Or if the two original non aggressive ones get along, you could put them together again with the little ones in their own clan.