It just depends on the individual fish you have of each species. If they arent breeding most firemouth are more bark than bite. The others I havent owned. Try it but watch out for conflict and be ready to intervene if needed.
GD's are giant danios .. as for an upgrade. I could , but im not looking too.. I can also transfer one of them to my 180G tank if there is a problem..
i honestly didnt think convicts would attempt to breed with BP's or FM's.. i was more worried about potential over load of bio...
I have 2 schooling fish in there as well to help deter the possible aggression.. but it seems overall most who have replied feel it can work ? .. great