Dividing one large, aggressive cichlid from a community setting is absolutely asking for trouble. It is (or at least it should be) common knowledge that cichlids housed by themselves can and usually will become much more territorial then ever. Therefore, IMO, dividing the tank until they catch up in size is out of the question. Provide adequate decor and the Convict's, as well as the Salvini and these will be fine. Your main concern will be either the Jag, Devil or Fh, either one one could destroy the other. Although the Convict's will act as dither's/target's that is certainly a nasty mix in a 150g.