Might depend on what you're trying to do. If you're living here, I don't think more than one is necessary, but if you want to challenge people with unknown teams of pokemon or like those in the gyms, having at least enough to cover their weaknesses to "types" would help. I don't think sheer quantity decides that, either way.
[ Says the woman with exactly two pokemon, and plans for a third only based on research and a certain dislike of these freaking ledges. ]
no subject
[ Says the woman with exactly two pokemon, and plans for a third only based on research and a certain dislike of these freaking ledges. ]