Russian forces have "likely largely stopped" being deployed as battalion tactical groups (BTGs), according to the latest Ministry of Defence (MOD) Intelligence.
The intelligence update highlighted that the BTG concept has "played a major part in Russian military doctrine for the last 10 years".
However, the MOD indicated that "several intrinsic weaknesses of the BTG concept have been exposed in the high-intensity, large-scale combat of the Ukraine war so far".
"BTGs' relatively small allocation of combat infantry has often proved insufficient," the MOD said.
"Decentralised distribution of artillery has not allowed Russia to fully leverage its advantage in numbers of guns, and few BTG commanders have been empowered to flexibly exploit opportunities in the way the BTG model was designed to promote."
Defence and security think tank, the Royal United Services Institute (Rusi) said "the most important determinants of victory are the actions of combined arms units".
"Only these units, in co-operation with other branches of arms and other military services, can perform the full spectrum of defensive and offensive tasks."
Rusi added that "the task-organised combined arms battalion has long been a feature of the Russian military; the BTG builds on this concept and is certainly something more".
"It is not only a tool of combined arms force projection but also a means of managing the training and deployment challenges inherent to Russia's tiered readiness and mixed manning system."