Eeeeeeh shocks and guards do compete because they CAN'T exist together. When guards weren't viable neither were any of those commanders and before this shock buff shock commanders suffered a similar fate. They compete directly with one another because you have to chose one or the other. Much like brit hammer and anvil design actually
No you do not have to choose one or the other. There 21 Soviet commanders and 10 of them do not have either.
And the "compete" logic is simply flawed, since it has to do with diversity and not balance.
Actually there is balance which has to with how unit and faction compare with each other and there diversity which has to do with how units with in the same faction compare to one another.
Lets say we buff Shock to the same power level of Guards making them equally cost efficient but now they compete with PPsh conscripts so now we have to buff PPsh conscripts because no one uses them but then we have to buff penals because no one uses and you end up with OP faction.
In the end you have messed up balance vs other faction in order to fix a diversity issue.