I'm not trying to be weird or anything, but, are things starting to get bogged down in 'limitation'? First, it's Territories, now it's Cores.
Just spitballing, but...
How hard would it be to remove static cores altogether and handle the Territory Unit itself as the Core for all static constructions on it?
'Tagging' honeycomb as generically 'static' (honeycomb that is not attached to a Dynamic or a Space core) would remove the issue of having to add cores to expand a base on a Territory and release the 'player tension' related to core limitations.
If the actual limitation on constructions is really how much honeycomb you can stack on top of itself to make buildings, then you can remove the core limitations for ground constructs.
For Mining Units and other (possible future) deployables, you could have a Deployable Core that can be placed as a temporary structure on Terrirtories a player wants use but not build a base on. A Deployable Core would preclude any further building on that Territory.
On claiming a Territory, player could have to declare the nature of the claim by identifying it as an HQ Territory (of the 5 permitted) of which the equivalent of an L Core area must be built on in order to substantiate the claim or as an Outpost Territory at a lower rate of rental on which only a Deployablle Core (smaller than an L Core) can be placed and no unattached honeycomb building can be constructed on that Terrritory. This way, you can build anywhere across your own HQ territories regardless, but if you wish to mine or place a temporary pvp outpost you can only have that single Deployable Core on that Territory. Thus the nature of the Territory defines what you can buld on it. Additional Territories could be claimed as Subsidiary Territory in the name of the player or Org.
Sub-Plot:
If planet based pvp ever comes into play, then the Territory Unit itself could be the 'Capture the Flag' objective, rather than repetitive core destruction (as in space combat) and a Land Grab objective could be determined by the aggressive deconstruction with weapons of any constructs on the Territory or by taking possession of them with an area-defined, time-limited Battle Unit that asserts conquest from the aggressor that must then be neutralized by the defender or must time-out in order for the defender to repossess their property... perhaps it should take the placing of ten Battle Units to control a whole Territory so an aggressor has to decide on the amount of firepower to bring to the battle and whether they want to posess or demolish the Territory and its assets and a defender has to decide which assets require the most protection.
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