I don't necessarily think it should be nerfed, just that it should be changed such that no synergies exist that allow the most expensive units in the game to be killed in one shot.
Which makes it even more important to change. When overpowered abilities are gated behind a few commanders, those commanders are the only ones you ever see and the meta becomes very stale. Soviets need other ways to take out these units. Preferably ones that involve more than clicking one button.
If soviets lack other options then that's a separate problem that should be addressed as well.
Romeo, that is a hypothetical situation. I am not saying it doesn't happen, but that requires so many situations and variables that i doubt makes it a common occurrence.
I know having those abilities makes the commander more appealing...but all the other commanders are very lackluster... Now you are proposing nerfs to B4, Mark Target.. ISU is coming soon...there will be no more Soviet late game.
And i disagree with your statement on discussing these balance changes as "vacuum" discussions. These units and abilities have a strong relationship to their respective faction design. Additionally, these abilities and units also have a cross-factional relationship to other units. Discussing Mark Target alone would ignore how the ability plays into the Soviet meta. It would be easier to discuss one unit and only one unit if all factions were symmetrically balanced.