why? he wouldnt know where hes going or if he will end up in the same place of that dimension as obitos bodyWhat if itachi lets kakashi warp him? That could change up the whole outcome.
You don't even know how Obito protected the Gedo so you shouldn't be making assumptions on what he can and can't do.
who said kisame is a non factor he defeats minato easy
Yes, I do. It was Kamui. Kakashi sends the Gedo to the other dimension and Obito nullifies it by using Kamui.
Not to mention, can't Minato tag his team then let himself be warped by Kamui, after which he tags the ground inside the other dimension and free travels between the two planes, making Obito's Kamui useless?