Show me how long they fought as he was one-shot given he was out for awhile. You don't know when fight finish, so why stating headcannon. Tell me about Beetle Gifter though on what is he doing? He still fine from when Zoro fought him.
KAIDO could have avoided this new scar, if he knew that ZORO has COC, but as ZORO used it by luck and KAIDO underestimated it, and didn't mind dodging or going with everything, he was hurt, but that doesn't take away ZORO's potential of being able to hurt KAIDO with his strongest blow and with ADCOC, this is his merit, although KAIDO is still fighting very well after the scar, feat of resistance, thanks ZORO.