I'm not quite sure what you mean. If you mean they are good for a community tank, I would have to disagree if they are ripping your shrimp to threads. It is only a matter of time before he/they get the rest of your fish.
Size does not matter when tiger barbs are involved. They will attack, and kill, much larger fish. They should only be kept in a community tank in groups of 8 or larger so that the aggression is lessened and directed more toward their own kind.