Well I would just like to voice my opinion, Kakashi would probably lose this battle but that doesn't mean that he is stronger. I'm sure there are tons of people that kakashi could beat that Guy could not. And Kakashi has a really good chance of winning as well. he probably knows just how to beat a taijutsu specialist. If I were him I would do a raiton bunshin like he did against pain that electrocutes whoever destroys it. Guy doesn't have much of a defense against that and there is no possible way to see if a clone is the real person or not. After that kakashi would have an easy time since Guy refuses to use ninjutsu. But if Kakashi tries for a direct battle then I see him losing.