illustration of the problem concerning greenzones:
image 1 coalition A declares war on coalition B, they create at the border with B on the "greenzones" several private claims with warehouses, houses etc etc to host their warriors, loot, siege equipment etc etc, they can ship from Coalition A to B with impunity, during Coalition B JH they have 2 choices: Either raid them from that advance spawn point and loot them or setup a FOB claim near Coalition B border, and during JH take over Coalition B terrain without being able to counter attack coalition A mainlands.
due to the central position of the zones, this is an issue as you create only a few areas where medium/small guilds may settle due to the danger of this tactic
Instead if you moved the areas at the 4 corners, it opens up the game, lessen the area and lessen the threat as there are islands etc etc to create natural barriers that would make Medium danger and danger zones less so as it would require enormous investments to move things there