I'm not exactly the expert, but I have kept some parachromis for various periods. Here is my experience:
Dovii: I'd say at equal sizes, the dovii just seems nastier. The fact that they get bigger than a jag means they will probably kill off the jag eventually (unless they are buddies). I'd also say the dovii has bigger/more teeth than a jag so these guys are just plain dangerous to tankmates. Having said that, I've also seen very shy dovii where jags tend to be more consistent in temperament.
Jags: Predatory...Eat just about anything you put in the tank. Territorial (naturally territory increases with growth) but the ones I have kept do not sound as aggressive as what other folks seem to have experienced. Now, I have kept aggressive cichlids so maybe my point of view is biased towards aggressive behavior. Also, I generally do not feed my fish feeders...which do seem to bring out the aggressive nature of cichlids. IMO, Jags make good "boss" fish (in an aggressive cichlid tank) since they don't seem to chase the other fish to death...just so long as the tank is big enough, the jag will remain happy in his spot.
I'm not going to say what you can and cannot do since each person will tend to experiment with different situations....that is part of the fun of fish keeping. I would however suggest not keeping a battered or endangered fish in a bad situation. I hate to see suffering (not to say you'd do that).
To answer your question, is it possible to mix a jag and dovii in a 220?..sure. If you get both fish at 1" and raise them together they may get along fine. Problem is, when one of them hits "puberty", problems may occur. Also depends on if you have a boy or a girl or mixes. I would guess:
1 girl dovii + 1 girl jag = coexistence long term
1 girl dovii + 1 boy jag = probable coexistence with possibility of breeding hybrids
1 boy dovii + 1 girl jag = likely 1 dovii and you're out the cost of the jag (boy dovii will vastly outgrow female jag)
1 boy dovii + 1 boy jag = very likely 1 (possibly irreparably) damaged dovii and you're out the cost of the jag
A 220 gallon tank is big, so your jag and dovii will probably be fine for a while...problems will likely happen as they approach 5 or 6". If you are torn between the two, get both (start small) and keep the one you like better...sell the other one and try not to wait until the one you don't like is beat 1/2 to death...harder to sell then.
Good luck and I wish I had space for a 220!
