So, you want an admiral to get serious over a bunch of fodders, who aren't even worth of a kick?
It's the only time when I see Kizaru fighting someone worth. It's a solid evidence. Akainu and Kizaru joined marines decades back and portrayed same as Zoro and Luffy.
And, you want Zoro to fight a person who became an admiral just 2 years ago because he has a sword?
lol, I wonder who would you put against Kizaru even when it's evident that Akainu and Kizaru are partners.