Batman is the greatest ninja warrior on the planet. Nothing can defeat him, nothing is capable of defeating him. He has saved an entire city countless times. He's a ninja. He's a cool rich guy. He was trained by the guy who trained Darth Vader. He survived a nuke. Ezio is a little b**** who loses to an arrow.
If Batman and Ezio squared off in a fight, Batman would win. Ezio is used to fighting in the shadows and using stealth to win. Batman fights head-on. A straight on fight would play into Batman's hands and Ezio would be at a major disadvantage. Batman would win and win easily.