Board Thread:Naruto Discussions/@comment-26084508-20150916103812/@comment-5936871-20150916180046

TheUltimate3 wrote: The belief that their strength is based on the number of tails seems to really only be held by Kurama, something Gyuki didn't necessarily agree with, and somewhat demonstrated considering the Eight-Tail should have been able to easily over power Two through Seven otherwise.

Realistically, there isn't a lot o evidence, when the series began, that Kishimoto thought of having more than two, Shukaku and Kurama. In fact, as I can gather there really wasn't any talk of there being tailed beasts at all until Part II. So it was probably more or less Kishimoto just deciding, hey I can run with this difference number of tails thing. That's true, but Gyuki did hold Isobu in place with only three tails and simultaneously punch Kokuo away. I believe that Kurama is telling the truth, as he has already proven himself as being the strongest and the other beasts disagree because they don't want to admit that they're weaker than Kurama who also happened to be a major asshole to the rest of them. Kisame also stated that Gyuki was the second strongest for some reason, and those Kumo-nin were restraining Gyuki in that flashback they said "The Eight-Tails has more tails than the Two-Tails so it's harder too capture" which can be simply interpreted as it having more appendages to fight with. But it could also mean that since it has more tails it's stronger than the Two-Tails. So I think the tails are used to not only make them unique but to demonstrate their power, it's just that the difference in power between the others isn't that big compared to Kurama.