I was thinking something smaller, like a shrunken version of Australia. If you use North America then much of the landmass should be unsettled and untouched by man
Which works to an extent . . . I actually like the idea that the Baronies were given widely spaced out areas with a bunch of vacant-ness between them to grow into though the strategic/economic important places are already given out.
My mental map is like this . . .
The Duke and his followers arrive in the system for their 'escape from the IS' or whatever other origin scenario you want to run and however they got the information on the planet. As the expedition leader, the future Duke & his family take the biggest prize as their territory. Each of the Baronies were the biggest contributors to the colonization effort- if the colonization was based off a purchased/established survey then it would make sense the supporters & future nobles 'bought' their baronies based on the estimated value of the claim/territory with their contribution to the colonization. Since the Port Royal original family were removed from power and exiled, they make a convenient example-
Port's founding family were planetary shipping magnates from a world the original Duke did business with, specializing in bulk goods shipping on his planet. The Founders became wealthy during the Star League, even having a few direct contracts for bulk foodstuffs to be shipped to the world's spaceport for export. With Foxhaven having a large amount of water (over 60%) but mostly in smaller seas and channels while the land is not giant continents, the future Duke determined it would be useful to bring in a shipping expert. Port's founder decided to leave the FedSuns with the future Duke as the First Prince kept annexing Hegemony worlds and armed encounters increased. Besides his family, Port's founder also recruited colonists from among his extended family and friends while making plans to sell off parts of his company to competitors. Port's founder used his liquid assets to buy a old Jumbo class dropship while also renting a Mammoth as part of the colonization expedition which were both filled with colonizing supplies (pre-fab shelters, livestock, agri-domes & seedbank, civilian fusion reactor, comsat) and supplies that let the future baron set up in his demense of one of the planet's most promising ports (quick construction 14 k-ton cargo ship, dredging equipment, shipyard equipment). Port's founder recruited roughly 6000 people for the colony though roughly 100 of those contributed to the colonization effort beyond their personal settlement requirements (pre-fab, work supplies, house supplies) with the 100 being Port's vassals rather than the future Duke's direct vassals. Some of those 6000 recruited people were actually going to settle around the Duke's capital.
During the first planning meeting between the future Duke and his Barons, they divided up the map based on their contributions to the colonization effort and their areas of specialization. Port's demense was a key sheltered anchorage off a channel located between the prime mining site along some unnamed mountains, the expected agricultural breadbasket, and where initial surveys indicated hydrocarbons should be easy to access. The besides negotiating for the original charter of of territory given using natural boundaries (size of Texas), Port also had included 300 islands/atolls of various sizes strung out into the seas on either side of the channel that bisected his territory along with initial claims for expansion dependent upon growth though that territory would be held by the Duke for the time. It was from ducal territory that several future baronies would be created and was a method to reward or punish the baronies at the time. Half the baronies shared a border with a single neighbor while the other half were so spread out they were not in direct contact with their neighbor. The Duke's direct territory shared borders with three of the baronies though it was not encircled by them either as it also had opportunites for expansion through Trust Territory.
