Yes, Zoro says that their ability to keep getting up reminds him of king, before he acknowledges any other similarities between them and King.
Once he realizes they have Lunarian blood, he tells them about his experiences with King without Vegapunk or anyone correcting him. Nobody says "oh wait, actually, the Seraphim have even stronger defenses!"
This is not in the manga. Point blank. Zoro describes King's defenses, applies it to Lunarians, Vegapunk walks off afterward and the matter is dropped in the manga. It is settled.

Yasheen what the fuck, which attack is stronger? Shishisonson or Onigiri?
Which attack did King eat to the face without damage?
Using outliers against King only makes you look deliberately dishonest.