One final question to you because I just want to make sure we are on the same page and let's keep it simple. Are you saying that a 4-5 inch Dovii will not survive or grow well in a 125 and then the move to a 220 will also not be a good idea. I am not talking about a 12 inch fis
I do consider a 125 a decent grow out tank for a 4" dovii, might even last a year.
At 12" (as some others have said) it will need to be moved to a much larger tank.
I consider 10 gallons of tank, per inch of cichlid minimal, but include height and width, beside length in that calculation in my tanks.
Tank size, has a lot to do with what any cichlid with tolerate in its normal perception of adequate territory for tank mates, the larger the tank, the more tolerant cichlids become odd sharing space.
Let me give an example.
I had a pair of Nosferatu bartoni in a 125, doing well spawning, and copasetic, so after the 3rd spawn, I gave them to a member of our aquarium club to BAP.
He thought because they were only a 5" L male, and 4" L female they'd be OK in a 55. Within 24 hours of putting them in that 55 gal tank with some dithers, the female was dead.