What do you think of Graft Calculators to compute how many grafts a bald area needs?

A graft  calculator (there are many) doesn’t take into account such things as hair mass index, a critical element for determining how many grafts one needs for a given bald area. To make my point clearer, image a fine hair (equal of a 1 by 1 piece of wood) or a 4 by 4 piece of wood). The 4 by 4 would have four times the mass of the 1 by 1. Then assume that the analogy is that a 1 by 1 is equal of a fine hair, but a 4 by 4 is equal to a coarse hair. The number of hairs (or grafts which contain hair) required will be significantly different so it is not just a number calculation as these Graft Calculators show. Then there is the ‘ART’ that allows an experienced surgeon to blend the numbers and the hair mass of the hairs and grafts into a plan. At the time this plan is built, the surgeon must take into account the donor supply (is it high or low). High density people with coarse her can do more to cover their balding area than fine hair low density people. To make maters even more complicated, imagine that you continue to bald even after the hair transplant.  Most people are somewhere in-between low and high densities and that is why an experienced hair transplant surgeon is critical to the entire process. I am not easily replaced by a calculator.