Well, if any Punjabi Muslims are, quoting your own words "harassing" Sikh women, then they would be, following the logic of the argument, "harrassing" their own. But even if we don't accept the fact that the division between people of different faiths varies according to time and place, there is hardly any genuine Punjabi Muslim that I know who either "harasses" or "looks down" on any woman let alone any Sikhni, Hindni or Musulmani. The whole argument is fallacious and conjectural. I think it is much better to reflect on the damage done to genuine inter-faith relations by sheer calumny and community hatred than it is to churn out completely inconsequential statements about "others" and "us". In the end we only degrade ourselves.
Punjabis, whether Muslim, Hindu or Sikh share a common bond of brotherhood and sisterhood no matter what the fanatics and fundamentalists of each community incorrectly believes. All the rest is amateur politics of the worst kind.