I wouldn't ask experts about application frameworks, I'd ask the people who use them. Similarly, drug experts, despite their profession, are not in a position to know the aggregate harm levels of various drugs. It's a misapplication of expertise and statistics, which apparently is the sort of thing the lancet has a fondness for.

If you wanted to make a legitimate measure of the harm of various drugs despite the inability to build a mathematical model, you could do a survey asking people about how often they use various drugs and their opinion of the harm they've been caused by various drugs (as user or non-user). You'd get systemic bias from peoples imperfect ability to judge harm but at least you'd have something instead of nothing.