The colonist signature ability Unmatched Expertise lets the colonist reduce the difficulty of checks involving his class skills. there is an upgrade that lets him reduce it twice. It has a minimum difficuty of easy.
Hypothetical scenerio: a Marshal (or politico that took ranged (something) for Well Rounded, so it's a carear skill) is shooting an Inquisitor at short range with Unmatched Expertise on for a 2 difficulty reduction. The inquisitor has Adversary 3, so if the ability wasnt in play, it would be a RR difficulty pool.
Does unmatched expertise reduce the difficult granted by adversary?
Is the final difficulty pool:
RR
RP
R
PP