I think air strikes can be quite efficient. From a plane a target can be well seen and the can be hit. That's not to say that ground personnel don't serve a purpose as well. But for me I think that air strikes are just as important and can do as much damage if not more.
Air strikes are undoubtedly far more efficient in terms of warfare than human soldiers. They can cover a larger space in a shorter amount of time, and are much harder for an enemy to retaliate against. Human soldiers can be ambushed or attached very easily, whereas an air strike would have to be taken down by a much larger and more precirse military force.
While I am far more for air strikes than I am for human soldiers, if we are debating on the efficiency, I believe the human soldier would always be more effective. For the sheer standpoint of accuracy due to proximity, the human soldier would always have the advantage in my opinion.
Human soldiers are able to target particular enemies more precisely than air strikes. It is my belief that air strikes kill many innocent civilians. This widespread devastation leads to many people on the ground turning against the attacking army, which makes keeping the peace much more difficult once the conflict is over.