"Vicious" Lol. Well they can be nippy but I have purposely put together a large school of tigers to keep them from picking on other fish and most of the time they leave everything else alone. Honestly when I add new things they can be aggressive, but after a few days they ignore new comers. (there are times newcomers don't survive the initiation but after the few days if they survive they aren't harassed any further)
The two convicts are most likely girls, which I planned- to avoid extreme aggression during spawning.
I am planning to get rid of the severums as they will put me over my stocking quota as they grow out.
And I do love my tiger barbs.