Again cap. If that were the case oda would not have had g4 luffy and lucci using attacks on things luffy stated were like kaido because of there durability (the seraphims)
What is the purpose of making the connection between seraphim and lucci? The Seraphim are invincible as long as their flames are not extinguished, there is a reference to the fact that the kaido did not collapse despite being attacked a lot. As long as their flame is not extinguished, they can't do damage to the Seraphims no matter who strikes them, and as I said, Base Luffy has shown feats that are far superior to Lucci's awakening form