@barnee
Soviet Partisan units do not control a territory. No matter how many Soviet Partisan units are in the same territory.
Soviet Partisan units can only spawn in Original Soviet Territories that are controlled by the enemy - but are unoccupied.
Example:
In Early 1943 Germany controls Belarus.
The Soviet Union has placed 1 Partisan unit in Belarus in Early 1943.
In Late 1943 Germany fails to eliminate the Soviet Partisan unit in Belarus.
So, on the Soviet player’s turn in Late 1943 a second Partisan unit is placed in Belarus - in the Place New Units phase.
The Soviet player decides to replace both Partisan units with one regular Infantry unit - and immediately takes control of Belarus.