This is the conundrum I faced a few months back. I had the choice between kakashi or minato and I based my decision based on this thought process:

If I go with kakashi susanoo, yes I could make a killer combo with jonin minato. However, I saw him as a ninja that takes up a position in your team that could have been given to a more versatile support ninja like gakido or madara. Whereas with edo minato I won't have to worry about making my mystery go through dodge because minato already does that on his own. Plus, I get the freedom of choosing an additional two ninjas to build my team instead of getting just one with the susanoo kakashi and jonin minato team (since you will always have to pick susanoo kakashi to make it work)

I see your point and yes that is the case for almost every time for edo minato. However, for the way I use him (with madara 5 kage and hopfully edo hashi in the future) which literally drains the opponent's chakra at round 2 giving me essentially a free pass till round 3 of dealing massive damage with little retaliation from my opponent. Of course, this is given that you have higher initiative or get lucky at round 1 of dealing acupuncture with chases. As I said, the thought process I had during the time is based around what i needed at the moment and the undodgeable mystery of minato and the prospect of getting him for kurama naruto's bond mystery outweighed kakashi's benefits.

But to the one who posted here's my just really general overview:

Kakashi susanoo

1. pros:

- Makes jonin minato and 6p naruto into hard hitting monsters

- Useful chase and mystery

- not viable target for chases

2. cons:

-Really low damage

- prone to cc

- somewhat limits team composition

Edo minato:

1. pros:

- undodgeable mystery

- immunity to cc

- has dodge

- scales with chase

- has bond mystery and required for kurama naruto bond mystery

2. cons:

-somewhat low damage early on

- long mystery cooldown

I personally prefer edo minato simply because the benefits I can gain from him exceeds the benefits kakashi offers. Plus he is very fun to use. This is my opinion on the matter given that I would rather spend give or take 20k coupons on him than on kakashi. Of course, it entirely depends on your preference and playstyle as well as existing ninjas you have.