Higher ranks need more dragon stones!!

Im a rank 157 , Ive beaten the story (21 ) and all 3 stars ) Ive been trying to get battle cards that I really want like vegito and goku black ssj rose , but the lack of story , missions and side quests to obtain these dragon stones is getting me to stop playing the game but to only log in daily Itll be really helpful and cool if the higher the rank you are and the higher the mission (like super hard ) will give you 3-5 dragon stones and more xp to level up there should be a difficulty called ultra hard where you fight bosses like broly LR And obtain 10 dragon stones and at least 100,000 xp ( or less?) but yea I think the higher ranks should get harder missions and better xp and dragon stones

Adapt_Hitz about DRAGON BALL Z DOKKAN BATTLE, v3.1.1