Hi BT. I think I get your drift. I keep a variety of tetras, always at least 5 of each but up to 10 of some. I have diamond neons, cardinals, lemons, serpae, black neons, rummy nose, red phantoms, glow lights and some harlequin rasbora. They loosely group together but don't shoal as such. I think the large number of varieties stops any one group shoaling and taking over the swimming area. It does help that the tank is VERY heavily planted and the fish are not always in each other's faces. Feeding time is the only time I see them all together, it quite a frenzy, but at different times of the day different species will be more visible than others. The only tetras I had a problem with were silver tips and they just took over the tank, so they were swapped out. Serpae tetras get a bad press but mine are really good in the tank. Environment affects behaviour a lot, I think. Hope that's of some help.
Sent from my iPad using Aquarium Advice