I guess that is a form of control, but not what I think of as control.
My idea of Control is the ability to turn it on or off at will.
If you destroy an insulator you are not going to be able to turn the power back on. The trouble with shooting out a transformer or insulator at a substation is that the average guy with a rifle will not know what that substation support. He may be taking out a very large area that may impact friendlies as well as foes. It could also cause a cascade that may take out all of his friends.
There is a lot to consider before you decide to start shooting a substation.
By the way a .22 or a squirrel will do the same thing as a 30.06.
Enough people will be so angry that they will only care that they still see light across the highway or RR right of way in “hostile territory,” and that will be enough to spur them to turn them off. Turning them back on will not be a consideration.