I don't know if this only occurs when using Easy Eights but there appears a little buff icon inside the unit's portrait which is called something like "radio connection".
This buff occurs when two or more Shermans are close to each other.
With the exception of the M4C Sherman, all Sherman tanks get this as long as there is an allied vehicle around. Captured enemy vehicles don't apply to this.
And soviets don't need more buffs? I guess, they need, and a lot.
And Allies have only 2 real officiers, actually - Major and Airlanding. LT is totally same riflemen squad, and Capitan is riflemen squad with pretty strange abiltiies, but without aura-effect.
In any case, adding Commissar squad or Command KV-1 would be very helpful.
They are all officers, if they can get XP while being next to a squad for causing mg fire or mortar fire, that is an officer.
The Soviets don't need anything like this as they happen to be a strong faction that uses doctrines to improve their playstyles.
Plus, no one wants a similar playstyle with the Sturmoffizier.