!st off that tank only large enough for 1 dovii, alone. When young, its OK for the cichlids as juvies
But as other posters have said, many of your fish will probably kill each other, making room for whatever is left.
Because you already have all but the dovii in the tank, they may attack it and put it out of its misery in such a small tank early, and the dovii will be a non-issue.
If the dovii does make the first week as it grows it will be interesting to see who kills who first.
Be sure to update this thread as deaths occur (or not) to see if we who claim aggression is imminent are just blowing hot air.