No, it doesn't matter how many people hunt with the dog. As long as the dog can circle rabbits there is no reason 6 people would be too many.
With only 1 dog on the ground you may have to do a little more brush kicking, just because one dog can't cover as much ground as say 4 dogs. For me it's nice to see a dog solo a rabbit back to the gun, there are too many out there that can't get it done by themselves.
i have not hunted with dogs all that much but whenn i have its been awesome. i grew up just kicking brush and trying to shoot them while all tied up in darn green skin cutters ha. i was just asking cause we are hunting with a guy who has a really good dog on sat.