Kakashi is stronger than Tsunade. He is faster, smarter than Tsunade, far better in ninjutsu, genjutsu and has sharingan to predict attacks, strong to avoid attacks, skillfull in fights(using kage bunshin as a support in almost all his fights). Tsunade has strenght over Kakashi though and is pretty much immortal. But she can be killed obviously. Her Byakuyou won't help her to regenerate parts of her body which are cut apart. Kakashi could feint her with a raiton kage bunshin like against Pain and cut her apart when needed. So i see Kakashi most likely winning here.
But Jiraya is stronger than Kakashi
