Minimum dominion?

[Twan]

I think the size / start positions of the map decides it.

On big maps or maps with spaced fixed positions I'd use even dom 3 or 4.

On typical random 15 or less prov/player maps where capitols may be only 3 provinces away I'd rather take 5 minimum, and usually 6-8 if my pretender isn't awake.

Also scales are a thing to consider. Taking good scales is a waste when your dominion is too low.