I think the main confusion comes from the original Neuroshima Hex! rules. For the description of board tiles:
Board tiles, as opposed to Instant Action tiles, are ones that can be placed on the game board. There are 3 types of Board Tiles: Headquarters, Units, and Modules.
So that is the part I am confused about; by this definition HQ and modules are separate from units. I have been playing the HQs as units anyway because that is what I have seen done on the forum, but after looking at radiation, I'm really questioning this issue more.
Essentially what I would like is a clarification and where in the rules it describes:
HQs and modules count as units
because that is what I am really not finding at all.