Just some food for thought:
-- Wouldn't any increase in the fatigue penalty effectively punish owners who are good at putting together an offense? Imagine 2 owners spending exactly the same $ on exactly the same # of PAs. One owner puts together a team that scores 4 runs per game, the other puts together a team that scores 5 runs per game. (I actually think this is a very conservative estimate of how much variation one can get in offense, especially if you allow for different parks). An increase in the fatigue penalty would disproportionately impact the owner of the 5 R/G team, because his players will accumulate PA much faster. This seems fundamentally unfair to me. He has not "gamed" the system by buying fewer PA...he has "succeeded" in the system by putting together a very good team...why should he be punished for doing so?
-- Wouldn't any increase in the fatigue penalty create an even greater incentive than there is now for owners to rush to Safecos/Petcos/Astrodomes? I think there is way way way too much use of these negative-offense parks already, and I would hate to see any major change to the engine that further encourages their use. Of course, I've long lobbied for the idea that you should have to pay for parks the same way you pay for players, with higher price tags the farther away you get from a park factor of 1.00, but as long as parks are "free" I think we need to be very careful about creating greater incentive for the negative-offense parks.
-- Wouldn't any increase in the fatigue penalty ultimately lead to an even greater reliance on the cookie pitchers? If owners have to buy more PA in order to avoid fatigue penalties, they will have to spend a greater percentage of their salary on offense than they do now. In an 80M league, if I can spend 36-44M on pitching and still be competitive anywhere in that range, then there are many strategies I can use to build a pitching staff. Those of us who eschew the Josses of the world (I think I've used 1908 Joss in an OL exactly once in the past 3 years) have other options to build a strong staff. If I have to spend more of my team salary on hitting in order to buy more PAs (or buy better hitters, so that they will still be adequate even with a fatigue penalty), then I have that much less $ to spend on my pitching staff, which almost requires me to only buy the highest value/$ pitchers. I would hate to see any change in the model that led to an even greater reliance on deadball era pitching.