The military on both sides is a bureaucratic dictatorship....not a democracy.. so when the Generals' war strategies dont work (The Ukraine's counteroffensive & Russia's conceding territory 20 months ago in the Kharkiv region to concentrate further south) then the norm is to replace the General (s) . This is self regulating to the extent that it "encourages" better ongoing war decisions at the top......otherwise the blame for failures would have to be accepted by Zelenskyy & Putin respectively.
