The longer the fight, the worse it is for Kakashi.

His Sharingan drains alot more chakra than an Uchiha's, and now that he has this evolved sharingan, it can only drain it at a quicker pace. Kisame having a huge amount of chakra, plus the Samehade, which can drain chakra, it isn't good for Kakashi.

I think this would be a good fight.