By the way, it just un realistic how minato saw a weak spot on chidori without even seeing the danm jutsu in action lol, that line should fit better if he sees the jutsu first then argue about it.
Which its not really acurate, because there it not much different btw chidori and rasengan.
all kakashi needed to really master the jutsu its has more reflex and agility, and able to battle at highspeed like now.. sharingan its not really needed to beging with, but at that stage of the jutsu it complement it for the lack of agility.