Maybe if theres one important reason why kakashi is the best hokage is that he overthroned the elders and so much more people during kakashi's 6th homage times, which became the start of bringing peace to the ninja world.
kakashi Probably knew alot about them and the other secret organization on konoha since he was part of the anbu
kakashi Probably knew alot about them and the other secret organization on konoha since he was part of the anbu