Although optimized for offensive operations, the FCS (BCT) will be capable of executing full spectrum operations. The FCS (BCT) will consist of three FCS-equipped Combined Arms Battalions (CABs), a Non-Line-of-Sight (NLOS) Cannon Battalion, a Reconnaissance Surveillance and Target Acquisition (RSTA) Squadron, a Forward Support Battalion (FSB), a Brigade Intelligence and Communications Company (BICC), and a Headquarters Company.
So the recon battalion (RSTA) is in addition to three line battalions. My guess is that there will be four companies (2 "heavy" with the Mounted Combat System and 2 mechanized with the Infantry Carrier Vehicle) to allow for balanced pairings of "armor" and infantry, but I've seen nothing that indicates organization below brigade level.
I can only assume that the continuing shifting of jobs held by soldiers to civilians will be used to fill out these units. The current BCT with two line battalions have eight companies total. Three four-company battalions require twelve companies and even a triangular battalion will need nine line companies.
Germany in World War II showed that two-battalion regiments could fight effectively in high-intensity operations as long as supporting firepoer was intact. The trend since the Civil War has certainly been for units to have a smaller proportion of line units. So I think we could do this successfully with our far superior supporting firepower.
But counter-insurgency requires manpower so I guess this lesson of Iraq is supreme for now. Though even two-battalion brigades could have additional units cross-trained for infantry as our deploying units do now.
