Each theme stretches over 3 colors instead of 2, so each archetype has 6 signpost uncommons in each of three color pairs.

WUR (Jeskai) - Artifacts
GWU (Bant) - Enchantments
RGW (Naya) - Modified
RGU (Temur) - +1/+1 Counters / High Power

Need to add proliferate

UBG (Sultai) - Self-Mill / Leaves Yard

add more surveil, threshold, etc.

BRW (Mardu) - Tokens / Low Power
GWB (Abzan) - Life Drain
WUB (Esper) - Legendary / Historic
UBR (Grixis) - Crimes & Outlaws

UR doesn't call this out ... waiting for BR to have instants and sorcs matter

BRG (Jund) - Delirium / BR Sacrifice non-creatures