Again.
There are ca. 1500-2000 US troops in the Kosovo.
According to your plan these troops are relocated to A-stan.
There we have 3500 germans in the north and a bunch of smaller detachements from other nations.
Those should leave A-stan and go to Kosovo.
So you have a hole of ca. 4000 troops in the north of A-stan.
You get max. 2000 US troops out of Kosovo to fill this hole.
You would need less troops than we do due to multinational forces tend to be tail heavier but this won't be enough.
So by performing your plan you get not even enough troops for the hole in the north not to talk of freeing up additonal troops for the south. And you kill the multinational idea of ISAF.