There's a video on youtube of a 375 litre (100g) tank with two large green terrors, 4 or 5 adult convicts, sajica, firemouth; and more, which was pretty peaceful from the look of it. The difficulty with making calls on videos such as these however, is that these are usually exceptions; plus as previous posters said, it'd be a LOT more work to maintain, and you'd possibly lose the attraction in a tank with fish that are too crowded to orient themselves. Could be missing out on the behaviour that makes these fish attractive in the first place 