IMO ur original idea would work although I'm not sure about the vieja. So if u remove it and the remaining BGJD's after getting a pair with ur EBJD, the breeding convicts will take up a little space in a 140gal. The texas might be harrased by the two pairs but then again you have a looot of dithers in there to keep everyone busy. I think with enough caves and decoration to break up the line of sight you'll be more then OK.