I am just giving Akainu respect here otherwise this fight aint very difficult for Zoro unless Akainu shows ACoC. Because then the clashes will be determined by haki, otherwise cutting magma aint gonna be difficult for Zoro who has shown being able to cut rocks and flame.
Jinbe can hang around a little, if he has access to water nearby then he can make life very difficult for Akainu, not to mention that he already shown being able to block and tank Akainus so called super lethality.