Board Thread:Naruto Discussions/@comment-26508646-20150722181739/@comment-734582-20150723122457

It's because he uses a normal Kurama Chakra Cloak in stead of Six paths Sage Mode Chakra cloak.

On rereading the entire Gaiden in one sit, i think it's fairly clear that naruto strolls through the fights like Hiruzen on an afternoon walk, and doesn't seem to think much of the Shin as an enemy. He was clearly aware of them and didn't seem particularly afraid or concerned, and he probably was already thinking of disposing of the Original Shin and adopting the rest. After all, having a few dozen kids with Mangekyou Sharingan around doesn't hurt Konoha's power.