Campaign 1: Remnant Fleet Raids
In the wake of the Battle of Demeter, the IMC Remnant Fleet has taken to raiding colony worlds, both allied and enemy alike, to secure resources to assist in their campaign. The 6-4 and Apex Predators have been contracted to eliminate these forces.
Maps: Homestead, Eden, Black Water Canal
Campaign 2: Restricted Property
With the chaos amongst the IMC following Demeter, many IMC bases and derelicts have become key salvage utilised by Militia troops. Vinson Dynamics seeks to recover these vessels and reverse engineer several of the key materials successes employed by Hammond Aerospace. The Marauder Corps has been tasked in the salvage of these critical pieces of hardware.
Attrition and Hardpoint on Drydock, Colony, and Relic
Campaign 3: Special Recon
MCOR troops deploy onto the surface of Typhon, having been tasked to assist an SRS research operation. ARES Division forces pursue them relentlessly. (This could be what happened to all those Pilots and grunts you come across dead in the campaign)
Crash Site, Boomtown, Complex, Forwardbase Kodai
Campaign 4: Urban Pacification
IMC forces move to pacify many Frontier populations in the wake of the destruction of Typhon. The Angel City Elite attempt to escape the pursuing forces.
Angel City, hidden Militia base on Rise
Campaign 5: Corporate Espionage
Vinson Dynamics mercenaries raid several critical IMC locations in an attempt to locate key research obtained by ARES division.
Exoplanet, Boomtown, Complex
Campaign 6: Simulation 5-Gamma
Militia troops combine a mix of Live Fire and simulated testing to prepare themselves for deployment. Maybe MRVN vs. ACES or MCOR or something.
War Games, Township, Boomtown, Deck, Glitch, Stacks and maybe Meadow and Traffic.
Not all of them could work well but I think there's enough there that you could work with.