You need to complete the final proud quest for the other medallion quest to unlock, otherwise you're stuck farming the extreme quest.
Those 2 quest are how you get medallions, the extreme quest just has slightly poor drop rates so it's very possible to complete the quest and get no drops at all.
I'm not entirely sure on this by the way but I believe completing the 2nd side goal in the extreme quest should guarantee 1 medallion, otherwise it's just entirely up to luck whether you get any at all.