Definitely not. I'm aware there are big name (third party) characters that would sell even better than the ones we've received. For example, even thogh I prefer Hero, I think that Sora would have sold better.
That said, I definitely think you're wrong about all three of those characters selling better than the ones we have. Even as someone who has never played Persona, I think Joker is one of the single best additions the Smash roster has ever gotten, just on account of how unique he is in the way he plays and his aesthetic and what he brings to the table. He was also the perfect first DLC character, in that he set the tone for the fighter pass as being fighters that people wouldn't see coming.From my own personal experience, I saw him drum up a lot of hype around the fighter pass that I don't think Rex or Springman (a character people feel pretty lukewarm about) would have. I think if Springman or Rex had been the first DLC announced, a lot of people would have skipped the fighter pass entirely, since Rex and Springman are characters that appeal to hardcore Nintendo fans who are already buying the pass.
Then to follow that up with with Bandana Dee, that's another one I don't think would have done super well. People who don't love Bandana Dee are indifferent to him, and would see it as a 4th Kirby character they don't need. Why spend 5 dollars on another Kirby stage and more Kirby music when you already have so much.
And to top it off, though I would personally prefer Waluigi to Banjo, I also understand that Waluigi is a polarizing character and a lot of people wouldn't buy him out of spite. And again, another Mario stage? more Mario music? Notice that besides ARMS every suggestion you make was for a represented series.
Obviously this is just my speculation on how this would play out, and I've proved nothing. So maybe someone else wants to give us a second opinion here.