What does the game use to calculate the needed Staff for an HQ? In a game I am playing currently I have 20 Staff in my HQ with a Staff % of 341%. In other games I have seen similar HQ's with the same number of Staff and same number of attached units display widely different Staff %.
It's the number of "power points" attached to the HQ. "Power points" are what is displayed on the units. Each staff is good for 10 power points. So an HQ with 20 Staff can fully "staff" 200 power points that are directly attached to that HQ.