Wait Sanji fainted from blocking King and Queen's attacks??
Zoro counter attacked after blocking Big Mom and Kaido's combo attack Hakai, and then counter attacked Kaido. Then Zoro went after Prometheus.
Then Zoro = Sanji doesn't add up now does it?
Then Robin's comment of Sanji being the wings of the Pirate King implying Sanji is either:
1. Sanji>Zoro
2. Sanji=Zoro
wouldn't make any sense.
I guess this confirms that Robin really was only talking from a position point of view as one of Luffy's main fighters, but clearly it isn't meant to indicate that Zoro and Sanji are on the same level in strength.