Different organizations treat it differently but 1 Million$ is considered the industry standard. In my opinion, the scale of corruption Pakistan has witnessed in the last 40 odd years these HNWI lists are meaningless, 1M$ is pennies for such people and if there is some data available about these exact people you will find most of them are not HNWI rather Ultra-high-net-worth individuals (UHNWI).
I know a few people personally who were appointed by the Sharif's, one of them made over 50 Million$ in about 3 to 4 years. This individual's father happens to be a senior pilot in PIA and had been acting as a personal driver to the family, this son was a security guard at JFK and once the sharif's came in power in 2013 he packed his stuff from JFK and landed at Lahore knowing he can get some favors, he got appointed as some hot-shot consultant(all he had was the typical fake accent) for a multi-billion rupee project, though legally speaking he was equivalent to a grade 16 officer however on the pretext of Pre-qualifying contracts, to the award of contracts, from mobilization guarantees to payments he got 10-15% percentage from different contractors. Long story short that 4 years of the job has brought him an entourage of super and hyper cars in US while before that he was driving a beaten up honda accord of 80s or 90s.
So imagine this is one story of someone absolutely no body and that too of grade 16 contractual employee, Imagine the people who have been working for last 30 years, the so-called career bureaucrats, the blue-eyed boys of the sharifs. This country is being robbed with both hands day in day out and unfortunately, I do not think IK can do anything about it, he probably doesn't understand the full dynamics how these people operate.