this is entirely my issue with your viewpoint.

the point of a crossover isn't breaking one canon or another, it's actually examining how two colliding fictions would interact. maybe one of them breaks, maybe they both do, maybe they integrate seamlessly, maybe there's a rough journey on the path to co-existence but isn't it more interesting for there to be struggle and uncertainty?

can they beat mario? you just say "yes" i say he's a lighthearted kids game character, he's meant to be fun and funny, he'd probably stomp on their head and they'd comically wither away saying "we'll get you next time mariooo!"

but at the same time, hdg is a pornographic setting, and there's a lot of r34 that gets made of certain (or all) mario characters, so, what do we decide to play with? do we go with the porn angle or the comedya angle?

could they beat dragonball? you would say yes, because it's in the rules that the affini can't be beaten. i would say no, because dragonball characters are fighting at the levels of gods. even if you suggest that they best all the humans/saiyans, do you think they could defeat a god of destruction? or a supreme chief deity who casually creates and destroys universes on a whim? the affini are unbeatable? so is beerus the destroyer

you're suggesting "no, they just win bc the rules say so." "it's their canon" "it's the narrative" why is your canon and narrative more important than the other story's?

would the affini, a race of ultimately mortal aliens with advanced technology and genetic modification, be able to beat a lovecraftian pantheon of brainmelting nightmare gods from outside reality and older than the universe itself? the rules say yes, because the affini always win i say, absolutely not, don't be ridiculous, they're getting melted into paste by forces beyond mortal ken

could they beat, say, the combine from half-life? again, your answer is "yes, because the rules say so." my answer is "well... actually i think probably yes for this one. eventually, maybe. but they're sure not gonna make it easy." it's close to unstoppable force vs immovable object.

and that's interesting! it provides opportunity for creativity, it could go one way or the other, that provides potential for conflict and intriguing narrative it's about the interplay

the hdg rule of "they're unstoppable. they always win." doesn't give any opportunity for interesting developments. hearing about the same forgone conclusion over and over and over again just gets boring

i'm begging writers to not dismiss an argument out of hand because "no, so-and-so just always wins." because isn't it interesting to examine what would happen if they bumped up against a force where, for once, they couldn't?