It only works when you need to calculate some round numbers or to quickly see if the calculations are logical. When it comes to a real life Rule of 72 is too approximate.
I've seen psychics make accurate predictions, on occasion. That doesn't mean that we should apply that technique widely.
The number of external factors involved in predicting CO ski lift tickets a decade into the future so immensely overwhelm the model implied by the Rule of 72 as to beggar imagination.
From the beginning you should know what skills your team lack. Sometimes you need the A persons. However, if you don't have that amount of money, search for those who can do the job. For the first days that's more valuable.
