The Soviets have a weakness that I have encountered, both in this mod and the basegame, which is their army's lack of both healing units and abilities. The only two ways to heal a squad are the Headquarter and the Field Camp, both static buildings. This usually leads to the degradation of units that are reinforced on the front line, as well as the inability to heal units that are low on health but still have a full squad (Ex: units hit by artillery or mortar), short of retreating the whole squad.
There are some suggestion that I would like to make:

1. A Medic squad, along the line of the British one.
   
2. An ability to deploy medical cache or passive healing for embarked units (like the 251) for the ZiS truck. I do think that, for an support vehicle, the ZiS has few utility abilities, apart from its gunshop upgrade.