Kakashi was portrayed to be able to low diff base 2 tomoe Sasuke and should still be superior by a decent margin against CS2 3 tomoe Sasuke. He takes this low-mid difficulty. If Sasuke manages to force Kakashi to clash black chidori VS Raikiri, Kakashi would get overpowered since Sasuke's chidori has senjutsu. Regardless, Kakashi doesn't need to clash his Raikiri with chidori, he can use his suitons to push Sasuke back and then have a clone of his finishing Sasuke off. Suiton waterwall counters any shuriken or katon in Sasuke's arsenal. Not to mention CS2 will drain Sasuke's chakra who can only use 3 chidoris max whereas Kakashi can use 4. Furthermore, Sasuke hasn't showed any resistance to sharingan genjutsu in part one. Lastly, pretty much all of Kakashi's skills and stats are much higher than kid Sasuke such as intellect, repertoire of ninjutsu, stamina, hand seals, speed, etc.