When it comes to the Jounin class, I would definitely consider Kakashi the strongest overall. The reason being is that he is strong in many areas. His strongest point would most definitely be his ninjutsu. But other than the ninjutsu , he is brilliant when it comes to strategy (not as good as Shikamaru or his father of course). His taijutsu isn’t half bad either. I mean he has to be Gai’s rival for a reason. The fact that his strengths are not focused in just one area makes him in my opinion the strongest Jounin.