Wait wait wait
We know for a fact that King's Lunarian powers make him more durable than Kaido
In fact King could no sell Zoro's Kokujo Tatsumaki, the same move that cut clean through Kaido
King could even no sell Zoro's Shi Shishi Sonson, a move stronger than Kokujo Tatsumaki
So, Lunarian durability >>> Kaido's durability is an obective fact
Like it or not
Now, the interesting thing is that Vegapunk thought that Lunarian durability at least needed to be tested against lasers, meaning that it wasn't an automatic given that a Lunarian could no sell a laser
However, Kaku IN HIS BASE FORM completely tanked a laser
And that was Base Kaku
Imagine Awakened Zoan Kaku further enhanced with CoA Hardening
So... we were talking about the funny guys claiming that CoA Zoro couldn't cut Kaku, despite a weaker CoA Zoro being perfectly able to cut even Kaido of all people... and how that assumption would lead to the nonsensical claim of Kaku being much more durable than Kaido
But it turns out that the claim was not that nonsensical!
Lunarian durability > CoA Zoro > Kaido durability
Lasers > Lunarian durability > CoA Zoro > Kaido durability
Base Kaku durability > Lasers > Lunarian durability > CoA Zoro > Kaido durability
Awakening CoA durability > Base Kaku durability > Lasers > Lunarian durability > CoA Zoro > Kaido durability
They weren't wrong after all, Kaku is actually much much more durable than Kaido!
This
... or simply admit that Zoro just blocked Kaku and stomped him away without attempting to cut him
Take your pick
PS Regardless, the fact that Base Kaku could facetank a laser is impressive