Afghan forces probably have an advantage over taming the Taliban simply because their cultural understanding of the Taliban is so much stronger than any American's. Imagine the Afghans trying to tame street violence in America. It's the same thing. Americans automatically assume that what they think will work in circumstances about which they know very little, and wish to know very little. Therefore, I think that Afghans have an advantage of cultural understanding that would be helpful in helping them tame the Taliban.
As a result of intense religious fervor, Taliban members are dedicated to imposing Islamic law on all Afghans. The Afghan forces, although clearly more responsible, are lacking of a comparably strong motive to fight. The Taliban will continue to operate as long as they maintain their perverse goals. The Afghan forces simply don't have the same will to fight.
The only way Afghan forces can tame the Taliban is with outside assistance from the United States and other countries. Even with the United States helping, the Taliban is a force to be reckoned with. How many times have our soldiers helped to tame the Taliban and then as soon as they leave, are forced to come back to the same location they were in previously? This continues to happen. So can Afghan forces tame the Taliban? It's obvious that they cannot.
The Taliban is far too strong to be tamed. Just last year 60 troops were killed in a U.S. led coalition. The Afghan soldiers are going to remain improperly trained, (but will be provided with weapons at the American taxpayer's expense.) Gradually pulling troops out of Afghanistan won't make a difference in the long run. I don't even think Afghan people are going to attempt to stand against the Taliban on their own.
Unfortunately, if change is going to come it is something that will be gradual. You cannot force people who are born and raised with tribalism into a civilized people. In fact, because of the layout of the terrain in Afghanistan you may never change the people. Now not all the tribes belong with the Taliban but they are the predominant and controlling force within that country. I don't think in our lifetime we will see them overthrown.
If you read books like The Taliban Shuffle you can learn what even those training Afghan soldiers think of their ability to stand on their own, and it's very negative. Nobody has faith in their chances off quelling the Taliban once American troops leave, regardless of if they're going to attempt to or not.