Afghanistan already has a structural problem with too many internal factions vying for power; that's what prompted the success of the Taliban, the first unified government for the country in 20 years, in the early 1990s. The Afghan government's credibility already suffers from overt political support from the West among the rural population (which accounts for ~75% of the population); how would formalizing a NATO-controlled Afghan paramilitary organization address of any of those problems?