Board Thread:Naruto Discussions/@comment-31278419-20170219200439/@comment-2006510-20170221092336

They are equals- Asura made the three-headed, six-armed battle construct to fight Indra's Susanoo after all. He didn't need an equally-awesome ability like the Sharingan to make that battle even, and afterward it repeated throughout the ages, including Hashirama vs Madara, and Naruto vs Sasuke

^Both sides are naturally skilled, to the point of draws and/or narrow wins, and the Sharingan didn't change that in the end. It would've gone the same way if both sides had an ability, or if both sides had none- that much should be obvious.