Neither item is unique, so you can double them up, and that’s just what every class wants to do with them in P1/P2. Mages want 2 of the spell power rings, locks want 2 spell power rings, paladins want 2 cauterizing bands, etc etc.
However every class can get at least 1 better upgrade in BWL, and some classes can get 2 better upgrades in BWL. So my personal opinion would be to give all the classes that will still be using one through BWL 1 (mages, warlocks, paladins, druids, holy/disc priests), and then once everyone has their first I would look at giving it to whoever wants it after that point.
That’s because classes like shamans and shadow priests want both as their BiS in P2, but in P3 they can find a better ring for both their ring slots.
Just my 2 cents though.