Army Group South Ukraine ended in 1944.
Revolutionary Insurrectionary Army of Ukraine was created in 1918.
Army Group Vistula was created in 1945.
Army Group Don was created in 1942.
Army Group Liguria was created in 1943.
Army Group Courland was created in 1944.
Army Group Ostmark was created in 1945.
South Lebanon Army was created in 1976.
Southern Expeditionary Army Group was created in 1941.
No they could not because armoured units were sent from Army Group Centre to assist Army Group South in the Ukraine and also Army Group North in the Leningrad area. This resulted in a critical delay for Army Group Centre in its march on Moscow. A delay which eventually meant fighting through rain, mud and eventually freezing winter conditions. This plus stiffening Russian resistance made the capture of Moscow impossible.
Sixth United States Army Group was created in 1944.
Twelfth United States Army Group was created in 1944.