ChallenGe credits make no sense

How is today’s challenge “Just Holdout” worth 3000 cr. I got it and I was just wondering how the credits for each challenge is determined, because 1000 enemies for just 3000 cr, not worth it

well, there’s no real way to get it in anything other than Score attack, but figure at LEAST 8 games to get it, maybe more, so your looking at least 2 hours?

Lucky I got the weekly yesterday - today I did the Campaign, and now off to a couple FF to get to 400, and I’m done.