Icecold---T rex,
Just because the last word is 'MISSILE' doesnot mean that they are similiar---ie the surface to air and the surface to surface. They are two different weapons systems, with different design parameters, different technologies and a different modus operandi.
The next step is the range---the farther the missile is launched away from the target, the exponential difference of technology involved is multifolds---to a layman---that means---the difference in shooting a target at 500 meters with a .308 sniper rifle compared to shooting the same target at 2000 meters with a .50 calibre rifle. As the ballistics, opticals and weather changes are taken into account so is the one round one kill at 500 meters is taken into account as compared to three to five shots neccessary needed to take down the target at 2000 plus meters. The issue is that for an incoming object at a high rate of speed, three to five rounds are one too many.
Longer the distance, the higher the factor of improbability becomes, which means that the missile will miss its target more often than not. Now looking at what happened with the FT 2000, seems like china is missing some critical elements in its technology for a 150 miles missile---if china could not find a solution for the troubles---I don't think pakistan has the ability or the know how to do anything about it.