>Second, no it doesn't work that way, that's the point of the Pareto principle in the first place, what is 80% is always 80% and what is 20% is always 20%.

I know, since that's the whole point I was making. That the OP picked an arbitrary side to give the 80%, and that one could just as well pick the other one, and that you need actual arguments (and some kind of actual measurable distribution) to support one or the other being the 80% (that is, merely invoking the Pareto principle is not an argument).