While that's possible, we could always have to face the big bad NPCs.  "Team" games usually follow this and are still enjoyable.  Even in this game Hufflepuff (a completely NPC House) has been setup to be the largest competition in Quidditch.  I'm not exactly sure what you've planned, but my only comment is can it not be accomplished with the same affect through the use of NPCs?<br/><br/>I mean unless the 3 of us are all going to be rivals, it doesn't seem like it changes things all that much.