The record of "arming the locals" is generally a poor one in Afghanistan.

Where local institutions (i.e. tribal institutions) are still strong, i.e. the Mangal in Loya Paktia, this may have some usefulness. But the Taliban are themselves a non-tribal organization which grew out of the breakdown of the tribal structures in the wake of the Soviet war and the civil war of the 1990s. Areas where the local structures remain strong are unlikely to be areas vulnerable to Taliban power in the first place.

Those villages most under threat by the Taliban are not going to be strong enough to fight off Taliban forces on their own, as those forces can leverage manpower and firepower greater than a village can withstand. Already many experiments in such have failed disastrously, as the village forces either made truces with the Taliban to avoid death, or went over to them with their weapons.