I never heard it say it was halved by the reaper dead seal. It's Yang Chakra was sealed, whilst Ying was sealed in Naruto, that doesn't determine how much chakra was sealed, he only sealed the darker side of Kurama. Also I think even if he is "halved" by what you say, I think he is still stronger than the rest even without his Yang side. Also if you look at Gedo Mazo and how the eyes open, you know the last spot is entirely for 9 tails, it's in the middle and at the center. While the rest are paired up. Just more information for you thread. But also in the manga Goku gave chakra to naruto near the beginning or middle of the fight. Than towards the end...(well before transition to another scene) he was given chakra from the other 5 tailed beast left out, and learned all their names etc. But I agree he is not the strongest tailed beast, because the 10 tailed juubi, is a tailed beast as well and it's end form. So yeah...that is pretty clear. and that just makes this thread pointless because the tailed beast are really meant to be 10 tails, and not seperate, sage seperated it for insurance of it not running rampant, and it would be easier for people to control smaller entities than a giant entity than only he can overpower.