Sorry, I meant the sets you can order of a certain rarity from the particular sets. (you get 1 of each card and people often buy 4x of a particular set if they first do buy them)
This probably sounds like a lazy cop-out but I personally think that Shadows Over Innistrad is by far and away your best bet. Just look at my set review if you want to get an idea of the number of playable Uncommon+ cards because it's a huge % of them relatively speaking. It's an insane set for multiplayer Mages.
Guilds of Ravnica - Commander 2018 - Core 2019 - Battlebond - Dominaria - Rivals of Ixalan - Ixalan - Commander 2017 - Hour of Devastation - Amonket - Aether Revolt - Commander 2016 - Kaladesh - Conspiracy 2 - Eldritch Moon - Shadows Over Innistrad - Oath of the Gatewatch - Commander 2015 - Battle for Zendikar - Magic Origins - Dragons of Tarkir
Green - Blue - Red - White - Gold
My meta: 3 or 4 player free for all, anything goes but boring games or broken decks cause a vote to end that game.