I'd put that on the large group side, personally, but then again on this site 'small' groups aren't as small as I thought they'd be. I guess it kind of depends on your roleplay. For example, while a small group for a casual plot-based RP may be four or five people, in Arena a small group would likely be quite a bit larger. Then again, I don't really frequent the Arena section. 

In any case, I'd put that on the large side.