I'd love to know how unit maintenance is calculated. It seems like I can disband one unit, get +5 gpt, disband another with no change, disband a third and get +1 gpt. I haven't discovered any logic to it. Maybe it's a complex interaction of unit type, distance from somewhere, and number of units. What's odd though is that there is a supply number (of "allowed" number of units??) in one of the advisor screens, but I've never come close to exceeding it.