The STRmod is a measure of the force that a PC's musculature (and momentum, &c.) adds to the inherent destructive capability (i.e. the base damage) of a weapon.
If one may add 1.5*(STRmod) to DAM when wielding it 2-handed, then why not also to the AP of the weapon when used in the same manner?
If you are the GM, it is your campaign--your "Gameworld"--and you may interpret the AE rules as you, the POWERS THAT BE (PTB), see fit. If the tiny, insignificant mortals in the campaign don't like it, then...teach them a lesson with a tidal wave, an earthquake, a couple of Brythunian wenches with VD...you get the idea. :twisted: