Who said that Indus civilisation and its psyche is limited in one particular area. If you look at folklore of Punjab (especially Southern Punjab), Gujarat and Sindh.. Its all shared. Hindko (spoken in Kashmir, Hazara) still got common vocabulary with Sindhi.
Punjabis got martial race status due to Sikhs (considering the Ranjeet Singh’s war just before British rule started). Gujratis, Saraiki people, Kashmiris and Hindko speaking belt was not martial.