Here is another game I came up with.
https://unlikely-characters-for-smash.fandom.com/wiki/Unlikely_Characters_for_Smash_Wiki
Go to this site. Choose a character. Try to debunk arguments listed on the character's page.
I choose Master Chief...
It's still recognizeable there. There is dedicated fanbase. Ultimate's sales in Japan is 3.8 million. It's good, but far less than half of overall sales. So why is Japan like holy grail of appeal? We had Japanese companies like Capcom and Namco getting western characters (some are not famous or popular in Japan) in their games. There is little to no excuse for Nintendo to reject western characters.
Sakurai never set this as a rule.
Melee, energy sword, gravity hammer, Spartan abilities, tons of assassination moves for grapple, etc
He has far more movesets when it comes to non-shooting than Samus and Inkling. And he actually has original games/lore to back up.
So I guess Lucas and Ness would look out of place. Did he also miss cutscenes and third point view from vehicle and weapons like turret and flame thrower?
He is not in charge of newcomer selection. He is known for joking.
Same for fighting game or Fire Emblem. Hell, it applies to pretty much any genre.