This isn't really a plot hole but I found this page interesting
From right to left we have Zetsu, Pain, Konan, Sasori, Deidara, Itachi, Hidan, Kakazu, and Kisame.
Except those aren't Hidan and Kakazu. At the very least, it's not Hidan, because he isn't a giant. And Kakazu isn't taller than Kisame, whom to my knowledge was the tallest character in the manga up until the Raikage with only Jiraiya and Asuma challenging him height wise.
It does makes sense (the tall guy) because we know Kakazu killed his previous partner, but I wonder who that giant guy was supposed to be?
the tall guy was probably sasori's partner, since after orochimaru left and deidera joined he had to have someone with him, me thinks so at least.
you also have to remember that kabuto got hit by a rasengan from a little kid
That's no excuse, as it was a normal rasengan, unlike Konohamaru's small one. Though, actually, it may have been smaller than a normal rasengan. We don't know how a normal rasengan looks, we just assumed Naruto's was normal since Jiraiya, Naruto, and even Kakashi used that size. However, Minato used a bigger rasengan with no problme.