Not sure how things have changed lately (was gone for about 10 months), but in the past a desirable 6* champ would require like 80-90m minimum, some even above 100m. Not sure where Leader lands, but I would expect needing no less than 80m, but probably a bit more. For 5*, I'd probably shoot for 25-30m.
God how the f are you supposed to grind 80m in 3 days do you even sleep