I would say that the author is correct, the Kashmir region and Pakistan for that matter have more in common with Central Asia and Persian cultural tendencies which have contributed to the distinctiveness of these two reasons, hence the uniqueness of Pakistan today and the continued struggle for independence by Kashmiri's currently under indian occupation.
While there does exist some spheres of overlap, the distinctiveness of each region is more significant.
Major road links leading into Kashmir were via Pakistan and Afghanistan. I think as time passes and the fixation on ''religion'' wanes, the cultural, political,historical and customs will pull these regions back towards their original Central Asian and Eastern Middle Eastern (i.e. Persian) roots.