Perfect example of someone who doesn't understand the manga and Zoro's fighting style.
It's not about whether he uses 1, 2, or 3 swords. It's about the number of swords he used the majority of the time.
When Zoro faced BM, Kaido, and King, he used 3 swords the majority of the time. If Zoro used a different number of swords, it was just a technique. Afterwards, you went right back to using 3 swords.
Zoro has used 2 swords the majority of the time against Lucci. That is no different than his battle against Hody, Monet, Pica, Hawkins, Drake, Killer, and Apoo.
The number of swords he used the majority of the time tells us the battle difficulty.