Some maps seem to position some zone masters as if they were the hub of a zone "wheel" with its subsiduary fields located at the end of spokes spaced around it.
Would it be better if the zone master was always behind the bulk of its subsiduary fields such that the default map would seem to be a series of "fronts"?
The zone master is then defended by the healthy fields of a rear ward zone whilst ensuring logistics to its own front line fields.
