Haha yeah when I first read that I was like.... At headquarters...?
But no. Despite what the Hachibi said, I feel that no. of tails means strength (and it's been evidenced in the manga). The Ichibi is the weakest, and Tobi could only control 6 paths at once. He was already having difficulty with just six. Adding an extra Bijuu to it would have made it that much harder to do.