I know with D3, the probabilities have to be played. You have to gauge how common what you need is, and how common what you have on is. If you choose a rare, you arent gunna get a rare. Gotta roll a common to see rare, at least in my experience.
Same company I would guess its the same implementation in D4.
I played Necro this season, one doesn’t need to care about stats when its broken, it all gets one shot, no need to stack a 2Trillion card deck, what you need is one more click away…