Last time I looked, this wasn't an 'Efficiency Rally'. Meaning most points win, not most points per mile. I've not yet ridden the IBR, but one rally in particular that I do participate in has the Jim Young Memorial trophy for the most efficient ride/rider (points per mile). My riding partner won that this year and we were 6/7th. The ONLY year the most efficient rider won, ever, was two years ago when efficiency was the criteria.
I'm not throwing stones, just pointing out, that's not the Holy Grail for winning a rally. Certainly helps to be efficient but sometimes you just can't, and often times, the big points require big miles. You can almost always score less points with less miles and be "more efficient".
Certainly PPM efficiency can be the difference between guys running very similar routes.