If the scoring spread is only 4 throws and the ratings spread from top to bottom among those players is greater than 40 points, then the ratings range will be narrower than ideal. The average of ratings produced will still be equal to the average ratings of the propagators which is always true.
I can only get on the soapbox so often. Hole design does matter but very few take the effort to actually gather and look at data and tweak the designs to produce better scoring spreads. Granted, many don't know how to do that which is why having some of the more experienced course designers involved can assist with that.
Rater of the tossed arc.