Jinbe struggling against human Who's who is just red herring probably and there is more to come in the next chapters.
Oda needs to make it feel like the SH are all gonna lose to end the act in the next chapters which he is successfully doing right now.
But I really doubt Jinbe, Franky, Robin and Brook lose now but rather Oda will be make the situation pretty hopeless for them as he always likes to do.