Board Thread:Naruto Discussions/@comment-24898250-20140730025315/@comment-3038994-20140805184921

Half the time Kakashi uses Lightning Cutter, he's not running at breakneck speed. Usually for a quick, well placed stab. He doesn't need the Sharingan for that, he's got Anbu/Jōnin level reflexes for that.

And not just anyone becomes a Sage. What could possibly be more likely is Kakashi finally figuring out how to combine his Lightning Release and his Rasengan together.