Have you met anyone who has visited Dharamsala but not McLeodganj? Also, have you found a person who visited McLeodganj without visiting Dharamsala? I am not saying that such people don't exist. I am of the opinion that if you explored only one of them, you might be there on purpose or on a tight schedule. Dharamsala and McLeodganj are often viewed as an intertwined entity when planning a trip.