Overthrowing the Taliban was almost a prerequisite for those types of strikes. The initial strikes and action in Afghanistan by special forces and CIA were almost completely reliant on assistance from the Northern Alliance - for which over throwing the Taliban was always the goal.

The initial air strikes (unguided from the ground) were totally useless. It wasn't until they got SF/CIA on the ground working with the Northern Alliance that they could get it working.

In any case, it would never have been as simple as 'leave it to the local forces'.