I actually do think Draisaitl took a discount, if you look at the cap increase from 8.5 to 14, it's pretty much exactly the amount of dead-cap (minus Campbell) that Chiarelli/Holland left on the cap.
8.5 (Drai's current salary) + 3.2 Brown bonus + 1.9 Neal buy-out + 300k Perry performance bonus = 13.9 million
Very interesting coincidence that's pretty much 14 million dollars.
It means they chose an amount that just randomly happened to be priced in already to the Oilers existing cap. He and his agent just looked at their cap and said "you're not using this cap on anything right now anyway, it's fair Leon at least gets that".
I mean maybe that's just random coincidence, it seems like a pretty big one though. The Oilers just happen to have pretty much exactly 14 million to offer Leon next year without having to move salary out.