Luffy's gatling has done the most damage to Kaido, was given 5 pages of damage and 2-3 pages of Kaido lying in aftermath.
Big Mom had her mouth wide open with veins popping out of her eyes seeing the performance of gatling, she was calling Zoro a brat while he did tatsumaki. Let's not over-hype. Kidd didn't cream his pants at Tatsumaki the same way he did from gatling either.
Tatsumaki did some damage, but putting it at the level of G4 gatling, given Kaido's instant counter attack and (given that he was focused on Luffy to begin with as this attack came his way) is a bit unfair I think.