Are we not addressing Batman's superior AP, skillset and wincons here? The only argument is in Lupin's favor, and that he could win because he has prep time and could catch Batman off guard (which is a very formidable feat to pull off) simply because he's "not prepared", none of the Batman's abilities were evaluated or considered. I'm hardly knowledgeable in DC or Batman for that matter, but come on. Batman might not have prep time, but it's not like him to let this be a shortcoming of his when going against another opponent, he's known for being a masterful tactician, arguably better than Lupin even, and can create a strategy in a very short timeframe to dispatch the thief in his tracks. His standard arsenal has just as many effective abilities as Lupin's with prep, and are arguably more versatile too.
Lupin with prep clearly gives him a better chance, but even with that I still think Batman takes this for better skill, versatility, superior AP, and strategy. Even without prep, it's only going to take Batman one shot to completely dispatch Lupin.
