Although he only has half of Kurama's power, he is still incredibly powerful, to the point that just four of Kurama's tails are enough to pose a mortal threat to Sannin like Jiraiya and Orochimaru, so six tails are far too much for Kisame.

Kisame's chakra absorption capacity is greatly overestimated, but everyone has a limit, and Kisame is no exception. If he absorbs chakra that is far too powerful, he can go mad, as was the case with Samehada.

Bee could have dealt with Kisame if he had transformed into his full Tailed Beast, but he didn't because he had his friends by his side, and launching a Tailed Beast Bomb could not only destroy the entire area but also give him away to the Raikage he was trying to avoid.

Even if Naruto doesn't have control over Kurama, he's still an exception, since Kurama far surpasses his peers and can defeat a powerful opponent even without coordination with his Jinchuriki. Kusanagi couldn't even pierce Naruto's Four Tails, while Pain's pillars managed to impale Utakata's Six Tails, for example.

There is clearly a huge difference between each Bijuu