Some of us have often chosen to PA for less than full, and it makes sense to me that a fighter would choose to do that... why not? There is no problem if a Ftr10 that could PA for +10/-10 chooses to use it for +5/-5, unless there was a problem with a Ftr5 using it to its full.
Probability sheets are a different matter. I've seen them online and frankly I think they are insane. Thank god none of the groups I've played in has this sort of approach to the game, because it looks like a form of mental masturbation to me. But even if I dislike it, I don't care if someone else wants to play the game that way! But it pisses me off if because a tiny FEW amount of people play it "the wrong way", someone feels like the game has to change...