You can keep them together, just make sure there are plenty of hiding spaces so they can all stake out their territory. Make sure you are keeping them in a large enough tank. I think most would agree that the fish you listed should be in at least a 55 gallon.
8 tanks running now:
1x 220 gallon, 2x55 gallon, 1x40 gallon long, 1x29 gallon, 1x20 gallon long, 1x5.5 gallon, 1x2 gallon
Gouramis, barbs, rasboras, plecos, corys, tetras, fancy guppies, swordtails, ottos, rainbow shark, upside-down catfish, snails, and Max and Sparkles the bettas.