An important point to keep in mind is that sensible standard weights are based on population-specific data.
For instance, the early 170lb figure is mid-40s US Army based data (if I recall correctly).
Picking a set of figures out of somewhere is a bit risky unless the population sample being carried has some relationship to the data which went into the particular set of figures which one might propose to use .. This is more a worry with smaller aircraft where population variability becomes comparatively more of a concern ..
... consider two reasonable charter extremes ..
(a) sumo wrestlers
(b) schoolchildren