The old HM:FWL book doesn't just have a map, and doesn't just list regimental deployments for summer 3025, it also has a list* of which provinces and worlds organize their military the way Marik does, or Oriente does, or Andurien does.
Seems like a pretty reliable way to start picking out smaller provinces.
*
Across the Free Worlds, many minor variations of the three primary hierarchies exist, due to local government edicts and traditional grants and dignitaries. Below is the military organization used by each state. However, few states, especially the smaller ones, adopt the exact pattern set by their larger cousins. Note that one world is even listed twice.Courtesy of Reddit user wycca. /Edit]
[Edit, May 15: somehow missed the Stewart Dragoons' Home Guards regiment on Stewart and Juggernaut regiment on Payvand. Now added. /Edit]