I developed a real disdain for these "character match-up" discussions ever since I realised:
-The whole concept leads to the laziest, cash grabby crossover ideas ever. If you are gonna make a crossover, you should at least try to do something more interesting than everyone having a super powered school yard brawl. Most crossovers don't even have interesting reasons for characters to fight. IMO, I think super duper fights with no context are boring, no matter how flashy or well animated they are. I'm more lenient towards stuff like fighting games because the gameplay adds a different kind of depth but even then, I'd really appreciate an attempt at interesting interactions. This is why the Adventure Tours mode in Mario & Sonic at the Winter Olympics DS is one of my favourite crossover things in general. It may be about sports, but the character interactions are fun, it's fun to explore using the abilities of different characters, and they are using their powers in ways we normally don't see, which is more interesting than Super Anime Fight Club #11318016454345678.
-You can't actually make accurate assessments in most cases because the laws of different fictional universes are different. One super powered move may not necessarily work the same in another universe, and the writing associated with each universe generally does not account for this. The only exception to this rule is stuff like Marvel and DC. Marvel characters mostly live within the same universe so yes, accurate assessments can be made in terms of how characters match-up.
-Having a character be officially stated as "unbeatable" or "without limits" or anything like that doesn't guarantee them a win against any character either because there are MULTIPLE characters with those kind of descriptions in official bios and such, or where the point of their character is that they can pretty much do anything. Off the top of my head, there's Saitama, Kirby (though I feel he's absurdly overrated in this respect, Nintendo did just give that infinite power label to him in Robobot IIRC), Rosalina, Superman, and I guess Goku sort of counts too (I mean "breaking all limits" and "having no limits", in practice, mean the same thing in a story). And while people usually joke about it, characters like Popeye and Bugs Bunny count too. At that point, you have to call a truce because these characters can just do whatever they need to win, and when you have multiple characters that can do this, there is no logic or reason you can use to say which one of these characters can win. And even with these grand, limitless powers, these characters end up being arbitrarily limited because having them just fix everything would not make for an interesting story (like how Saitama has to deal with being a "low ranking hero" despite his strength, or the fact that Rosalina just flat out didn't whoop Bowser's *** the moment she sensed the Power Stars being stolen in Galaxy because we wouldn't have a Mario game if she did that).
-The discussions often turn into dealing with insufferable science jargon that wasn't even accounted for in a character's design, and general condescending behaviour that really makes me regret being associated with "nerds".
-Most of the time, I like both characters in question so really, the last thing I would want is for them to fight to the death or something, and they usually shouldn't have a reason to either. I remember a time where this guy kept arguing that Sonic could "absolutely curbstomp" Rosalina in seconds. He also would try to come up with fight conditions that were so OBVIOUSLY designed for Sonic to win (even though they really wouldn't make a difference in the end). And the only reason I argued was because of the absurdity of what he was saying and the misinformation he would spread on both characters. I argued with this guy for AGES, but I eventually just gave up because I realised that arguing about it was stupid. I love both characters, and the last thing I want them to do is get in a fight, and realistically speaking, it would make absolutely no sense for either character to fight each other like that in an actual story.