Queen confirms that his move can't be tanked by strong CoA haki user, so even Zoro would have his bones broken if he doesn't immediatly free himself or something.
And I remember people saying that haki is what really matter, but apparently Sanji got something better than top level armament haki for defense.
Queen also suggests that the raid suit alone is more durable than top level armament haki, which debunks people saying that "Zoro abs were > raid suit Sanji", Sanji tanked easily the blow of King, if someone like Zoro doesn't protect himself with swords he would die wjth an hole at that blow, that's what manga is saying here.
Now Sanji is already more durable than top level CoA haki armament characters, Imagine him + raid suit...
He can now withour a doubt tank the hakai for a 1 second like Zoro and he will also regenerates his bones.
Now I am not saying that Zoro is a glass canon or enything, him protecting himself with swords and armament haki can be on the level of Raid Suit Eskeleton Sanji's durability, I am just saying that his natural body is not as durable as Sanji's one, even if he uses haki on his body.