Though example of Raja Dahir is stupid but there is no need of making a hero of Raja Daahir. Raja Daahir had enslaved lical Jain and Buddhist population and took over their religious places. Local population was made achoot. - after forced conversion. Further he was a hindu raja and his conduct and exploitation is well known., he was exploitatively with limited roots in Sind.
Further Sikhs, at the time of Ranjeet Singh, were less than five percent of Punjab (census around 1870 puts Sikh population slightly less than 5%).
Before Ranjeet, Sikh Misals were essentially organized gangs of Dakoos and marauders who had ruined Punjab's economy and social life, constantly attacking landlords and villages. Muslim and Hindus landlords and villages alike. Later Ranjeet stabilized and consolidated this Dakoo rule (mainly using gangs concentrated in two Punjab districts. Sikh rule history is very cruel for both Muslims and Hindus. They heartlessly raided small cities for loot, with thousands and thousands of civilian death . Just for example, my own district in Punjab ( which'd make 4-5 districts today) kept fighting Sisk rule and never accepted it. In out local folklore it is called dakoo rule. Read any book of history of Sikh written at the end or beginning of 20th century or old documents of 18th century , not religious motivated history.
Point is that stop teaching us history -it sounds too andbhakt- past is past and we need to move on but you comment is no less stupid than the one of Irshad Bhatti.