I’ve had mine together and so far there are no issues. I have a male with a few female bettas and some guppies. I also have a female gouramI with a bunch of mollies and she got a nip at the ventral fin (probably a molly). Or maybe she did something strange and got hurt
Most likely, because their species are like cousins once removed. Unless you got the most docile of both species, I think that they would fight. You could do a divider if you wanted to get the one that you don’t have.
I would also like to add I have a female and male blue gouramI (which are supposed to be super aggressive or at least on the more aggressive gouramI side) but they love the community tanks they are in and I haven’t had any problems so far they’re about a year and some old now.