So no edo jins...does Kabuto have Edo Tensei?
Honestly, you've pitted my 2 favourites against each other. And without ET Kabuto only wins because of the location. The location is literally tailor-made for his fighting style and even Obito cannot defeat Kabuto here. Izanagi is literally one of the only attacks that can defeat this fighting style and it's something Obito doesn't have. It's a very good fight but Kabuto can pull this one. He can literally use the cave to crush Obito before using the 1000 other tactics of his from the shadows.
Outside of the cave, Obito takes it with med difficulty. No question.