Because you have to go by what the manga shows us, not what you want it to be. We have seen Zoro use 2 swords the majority of the time. That means he used 2 swords the majority of the time.
When the battle started, Zoro was using 2 swords. When we saw the battle in the next chapter, Zoro was using 3 swords. In the very next chapter, he was back to 2 swords. When the manga returned to their battle after the flashback, Zoro was still using 2 swords. That means he's been using 2 swords the entire time.
Plus, 3 swords, Zoro, are stronger than 2 swords, Zoro. If Lucci was too strong for 2 swords, Zoro would have switched back and used 3 swords, but he didn't.
Zoro vs. Killer was a low-diff. Zoro didn't use any 1 or 2 style name techniques like you did when he fought the zombie Ryuma. That once again shows how much he was holding back
Yes, Zoro is huff because awakening Lucci is a strong opponent and not easy for him to beat when he's using 2 swords and zero-name techniques. The point of the battles to show us Zoro with just 2 swords is YC1 level.
And I'm telling you, that's not how it works. We are going with what the manga showed us already, and it showed us that Zoro is still doing the same thing he did with Lucci, with or without 3 swords. Zoro is a character that changes his sword number according to attacks, like he did against Kaido and such. You can't decide how Zoro is doing with only his sword count. The context of it is what determine's how much effort Zoro puts in and such. For example, even though Zoro was using 3 swords against Pica the majority of the time, he wasn't putting in as much effort as Lucci.
3 Sword The Zoro attack didn't do anything to Kaido, while Kaido had to dodge one sword attack. its not about swords; its about how much effort Zoro puts into those swords and attacks. Yes zoro's ultimate attacks with 3 sword so he is able to perform his peak attacks with 3 swords but that doesnt mean every single 3 sword attack is stronger than 2 and 1 style.
The fight's diff isn't determined by how much they were holding back or not, bro; its how the fight is going. I can say the same thing about Killer: how he didn't have his scythe's, which Killer was saying, "If I had those, you would be dead" and such (we don't take it as face value because the result would be the same), but I don't because that's not something that determines the fight's difficulty. especially if its about Zoro's sword count.
Zoro already fought Lucci with 3 swords too, bro, and Lucci didn't use any named attacks either. Your idea of named attacks doesn't work here.
Zoro is Yc+ with everything he got, as we saw with King. fight 2 sword, no bandana, no left eye = Yc1 doesn't exist.
The fight is already mid-diff, and if Zoro shows any damage (not just cheek scract btw but some damage) or an extreme level of exhaustion, it will be a high-difficult fight. which is perfectly fine for Yc+ vs Yc1