Thanks, Cardinal Ape.
Loki100 has provided me with a link to the AGEWiki where the topics of Narwhal's Guides are covered, as well as many other interesting and practical topics (e.g., Pursuit, Supply, Retreat and Routing, et al).
Here's the link: Frequently Asked Questions about Concepts and Game Rules
From what I've read, it appears that Supply in other AGEOD games is very different from AJE. Otherwise, the information in the topics listed on the AGEWiki FAQ: Concepts & Game Rules
page seems germane to AJE.