Still want to cut about 200 cards.
Added the promo pack shock lands even though I dislike the art. Not sure if that's fixing the problem. After trimming 100 ish cards last week, the guild identities are starting to show. Had 3 drafts where I successfully drafted a 2c deck, although not entirely sure about their power level.

For reference, Vintage cube has 540 cards

I think, to do that, we really need to zone in on the identity of each guild.
Azorius: control? fliers?
Boros: blitz (Assemble the Legion and Deafening Clarion are the only control cards)
Dimir: mill, surveil
Golgari: attrition, grind
Gruul: stompy
Izzet: spells
Orzhov: bleeder
Rakdos: destructive aggro
Selesnya: tokens
Simic: ramp