From what has been read, kaido is the weakest yonko
He's taken no lasting damage, and as you say from what has been read, we haven't seen his hybrid or awakened forms. His full zoan seems to be slow and sloppy for AoE, just like G3 is for Luffy.
Shanks should still be stronger than Kaido because he not only stopped Kaido from coming to Marineford but was able to disengage and reach Marineford uninjured, but he should have roughly the same level of personal strength as Big Mom, and less hax than blackbeard, so yes he should be the weakest of the 4 yonko, which is why Luffy is beating him first, but to downplay him because of his performance here when he is not taking it seriously is a bit unfair imo.