In summary, a BTG is not a maneuver formation in the traditional sense; it will not close with its enemy to destroy them through firepower and maneuver. Instead, it is an asset provider to relatively static paramilitary units who, in turn, act as a guard force for the BTG and deny adversary personnel access to the geographic areas the BTG is assigned to control. However, the BTG is capable of extremely lethal strikes against its adversary and will execute those strikes whenever both assurance of success is high and the risk to BTG personnel and equipment is low. With that in mind, U.S. BCTs should employ tactics that make one or both of those criteria uncertain at best.
The Russian brigades that provide those BTGs can provide some replacements from the remainder and generate more replacements for those BTGs that the brigades formed, but that still means that the BTG is essentially the brigade in the field. And that support could be across the country too far to sustain the BTG in heavy combat.
As I understand it, some brigades can generate more than one BTG, but even combined those BTGs are less effective than deploying a 2-battalion brigade would be.
The result is that those BTGs are strong in firepower but fragile instruments that rely on local militias for some of the support that a true brigade would have in the field.
Stop treating these units like some revolutionary development. They are a means Russia is using to cope with lack of readiness in their army to put some combat-ready forces in the field because the brigades just aren't ready for combat.
