If I'm understanding this correctly, there's 2 parts for this.
Part 1 is that Super Fusion got "absorbed" by the dragon Yubel so it scales to 2-C. And part 2 is that cards (in this case Super Fusion) scale to their users.
Now the problem that I'm having with these two is that, first, why would we assume that the Super Fusion card got absorbed by the dragon? It doesn't really make sense to me, and not how cards function in general throughout the series from what I can recall (granted it's been close to a decade since I last watched YuGiOh). Yubel just used Super Fusion on the dragon, I don't understand why we would jump to the conclusion that it somehow absorbed the card.
And the second part of the cards scaling to their users seems like a leap too. The only time where the energy and bond, and whatever, happened between cards and their uses were in direct cases when that specific card had emotional value to the user. Random cards scaling to their users is very demonstrably just not true, because, pretty much, every single person in the YuGiOh verse uses cards, and they're very obviously just regular humans at the end of the day. The argument that "random bandits" also isn't very strong because this was back in the Egypt days, when "cards" didn't even exists, and the monsters there were directly tied to the soul/emotion to their master. Even in the scans provided the bandit's emotions were so strong that it physically manifested the monster from his soul, which wasn't what was happening with Yubel.
And I don't see why we would circle this back to Yubel scaling to Super Fusion's effect.