It depends on what ninjas you have and use. Your power and initiative is also going to be a factor. When you use susanoo kakashi you usually want to have more initiative, though he can still work quite well. Edo minato has a 3 round cooldown which is a big weakness but you can run wind main (or something like gakido). I would usually say edo minato. He's cheaper than susanoo kakashi too.

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)

Kakashi susano'o shines the most if you use him together with, as a move 1, or naruto sage of six paths or azure fang.

Minato edo tensei strictly requires reducing cd ninjas (like gakido mystery y version or dance of impetus) or to be the move 2/3 of other ninjas that let him stack and survive up to round 3 (water main, edo hashirama) so that he uses the buffed mystery once to deal massive damage or to round 5, to use the mystery twice (battles between full stacked with secondary stats lineups)

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.

^ There are some ninja those chases will never miss like Kurama.

S. Kakashi + Kurama combo is guaranteed hit.

Edo Itachi or M5K can't dodge his chase.

But if i was you that have to choose between these two. i'd take Minato also, personal reasons. :)

Nothing really much to think or to discuss about this. Minato - decent pos1 ninja. Kakashi - merely a support, and not worth 20k. Easy replaceable as support too. Probably worst of 20k ninjas.