Issho vs Zoro, Why Zoro would lose

Now the purpose of me putting this thread in the Manga discussion section instead of The Arena is for two reasons. The first is the fact that this has become a very huge topic among the One Piece fans lately, and it has taken over the discussion of many threads. The second being is, I'm not here to try and debate as who would win in a fight, but rather to give you my reasons on why it does not make sense for Zoro to be able to defeat Issho at this time.

The first subject I am going to...

Issho vs Zoro, Why Zoro would lose