Always 3 is better than 2, 4 is better than 3, 19 is better than 18 and 20 is better than 19, etc. And if You have possibility to have better skills with the same price and salary it is always useful. But it's obvious and it wasn't essence of question.
HN = 2 is acceptable minimum on every level. I saw successful NTs and U20 with PF/C with low HN so it shouldn't be big problem in div V.
In final result we have only points so conversion to points is proper and simple method.
Finally every skill increases number of scored points by own team or decreases number of points scored by opponent.