I have both duped as 4*. Don't use either for much besides arena. I haven't even felt compelled to use t4b to bring them to r4 so I can't imagine using t4cc to bring them to r3 as a 5*.
Take it with a grain of salt though since I don't use either of them very much, but probably not worth the resources to r3 them imo.
I've heard of people using Iron Fist for legend runs as a 5* R4, he is able to deal extremely high damage with his cumulative armour breaks. Coupled with double suicides, he is an absolutely beast and tears apart any enemy in his way. I'd go for iron fist even if he is just gonna be R3, I'm sure he will deal great damage.
Moon Knight is only so good during certain times of the moon phases, that's why I didn't choose him
Is iron fist still a viable option for legends run, I thought that was prenerf? pretty sure he and the other crit damage champs all took a big hit then, moon knight has a decent output damage and during full moon phase he is an animal, but I would only r3 if you have already got a gwenpool to that rank (or 4* r5 as she is the best skill champ, I would probably rank an unduped hawkeye before moon knight as well
it really depends on who else you have and what you need them for. Both would pay dividends in the arena over time. I agree that you will get more milage out of IF in quests, etc.
Any dupped 5* is worth a rank 3. Maybe not all are top priority, but in the end, 5* will be the core of the game for a couple years (before the joke that are the 6* will be "up-rankable")
Comments
Take it with a grain of salt though since I don't use either of them very much, but probably not worth the resources to r3 them imo.
Moon Knight is only so good during certain times of the moon phases, that's why I didn't choose him