the largest unit I was going to propose would be the Regimental Combat Team, which lets face it is more of a Mechanized Infantry Division. it was already a great system, provided you could transport it all, for offensive operations. mobilizing an RCT basically says "That planet is mine.
the BCT concept is best utilized for rapid response to threats and opportunities, and I figured would be very modular. if I am wrong I am wrong though *shrug*
Sometimes even a RCT wasn't enough.
I completely agree that a smaller unit easier to move around makes sense but the degree of standardisation you were bringing into the BCT seemed overdone. So the Division, equivalent to a canon RCT, can be broken into three or four Combat Commands which would range between 6 and 10 battalion equivalents, while letting each Division come up with its own preferred specific organisation.
Plus there are independent Command Command/Regimental Combat Teams like the Argyle Lancers or New Aragon Borderers.
The classic AFFS 'Mech force is a 'balanced' company with a recon lance of Javelin/Phoenix Hawk, an assault lance of Enforcer/Blackjack/Centurion and a fire support lance of Valkyrie/Dervish/Griffin. Where heavier 'Mechs are available the assault lance may gain Marauders, Victors or even an Atlass, while the fire support lance may be replaced with Rifleman and JagerMechs. Because many factories in the Federated Suns are near the borders or have been destroyed over the years, they cannot rely on replacements so salvaged DCMS and CCAF 'Mechs are important to them, but so are support from armoured regiments.
When it comes to heavy armour and massive firepower the AFFS doesn't look at 'Mechs: it looks at the heavy tank regiments of Manticores, Behemoths and Partisans, backed by a plethora of missile carriers. They also have excellent recon elements with specialised Darter scout cars, Ferret light scout VTOLs and Boomerang spotter planes. Davion light tank regiments, using the Scorpion and Striker, are more commonly found in garrison posts and the March Militias, but attrition has brought some into frontline Divisions.
