Second of all, the attitude moving the Marine Corps to throw Tanks and LAR to the reserves would be an attitude of "lighter, more expeditionary." With that, you'd probably see a gradual shift away from the 155mm in Artillery as the standard tactical artillery piece to something lighter. For example, we might move to the 105mm, while maintaining our current 120mm mortar capability.
In spite of phasing out the 155mm from Battalions, we imagine the Marine Corps would maintain the HIMARS because they provide a much higher cost-benefit, and are the best GS weapon system the Marine Corps owns for shaping the battlefield. If we hold onto them, and we should if we went down to 100k, then the Marine Corps should organize them and any 155mm howitzers the Marine Corps keeps in the inventory into a Force Artillery unit.
In regard to the airwing, not really sure what would happen there. One thing that was brought up was that there'd be a possibility of dropping fixed wing altogether, focusing on our VTOL platforms. If we did get rid of most or all of our fixed wing, then it would be natural to see the shift mentioned above in artillery to HIMARS and mortars, both of which have high angle trajectories, making it easier to deconflict with our Cobras and Hueys. That said, 105mm howitzers at the Battalion Artillery, and 155s at the Force Artillery level would still be important to give a sufficiently wide breadth of fire support options.
In regard to the "macro" organization, we imagine there'd be two divisions, each comprised of two expeditionary brigades. Each brigade would be commanded by a Colonel, and would be comprised of two infantry battalions, an artillery battalion (-), a mixed rotary wing squadron, and a logistic battalion minimum.
More on the supporting establishment, and reserve force structure later.
If you have thoughts, please comment below.