Another possible source

http://www.tribuneindia.com/2010/20101107/spectrum/main1.htm

Also

CIVIL AND MILITARY RECRUITMENT OF EUROPEAN AND NON-SIKH OFFICERS IN THE KINGDOM OF MAHARAJA RANJIT SINGH: AN ANALYSIS
Shah Noor, Mr.
Journal of European Studies, [S.l.], v. 34, n. 1, p. 82-93, jan. 2018.

Abstract
The Kingdom of Ranjit Singh was officially called Sarkar-e-Khalsa. It covered almost all of undivided Punjab as well as Kashmir, Gilgit, present day Khyber Pukhtunkhwa and Multan. His forty year rule saw communal harmony and peace. This study focuses on the multiethnic and multi-religious policies adopted in bureaucratic recruitment. Not only were the upper administrative echelons filled without any discrimination among Sikh, Muslim and Hindu inhabitants, European civil and military personnel were also appointed on key positions. Ranjit Singh’s realm was under constant threat from British Indian territories, not to mention a hostile Afghanistan on the West. Therefore, domestic tranquility was an existential necessity. It could only be achieved if all communities were seen rather equally.

http://ojs.asce-uok.edu.pk/index.php/JESASCE/article/view/262