The way Germany did it is they all drop as 2 stars, but rares and supers give 25 frags each dupe and they're around like 190-250 for a super so a 3 star super still ends up around as much as kage.

They're all usable as two stars imo but kage rares are always going to be useful with their passive so you need a little of both.

Good common rares from edo tensei like gnw tenten and the rares and supers aren't bad by any means. Really all about what you prefer at the end of the day.