Steward
Steward concerns settlement prosperity and estate or town administration. The party guide describes a Quartermaster with high Steward skill as contributing to maximum party size, with that bonus stacking with clan-level bonuses.
How it works
The skill page ties Steward development to gaining party morale from food variety as Quartermaster, improving settlement prosperity and projects as Governor, and spending time in settlements as Clan Leader. The guide recommends developing the player's or Quartermaster's Steward skill early, but gives no exact party-size values.
When it helps
Prioritize Steward if increasing party capacity is a key goal.
Your next step
Gain morale from food variety in the Quartermaster role, or practice the other stated role activities.
Read the supporting references
Check the edition and source version for patch-specific details. Guide methodology.