Over the course of a season, it will have effect of giving either more ABs to pitchers or taking away starters innings.  

But how many innings?  What is the quality of those innings being lost, versus what their bullpens offer?

How does this increase in workload affect the quality of the bullpen?  If one or two SP innings are lost per rotation cycle--which I think is a reasonable guess--that ammounts to ~50 IP in a season, or the work of a good reliever.

Do starters benefit from the lighter workload? What is gained from the small increase in the percentage of PAs dedicated to pinch hitting?  Does this arrangement really lead to getting more guys on base in front of Pujols at all?  Is that inandof itself a good idea, or does it lead to Pujols getting pitched around more often?  Would it be better to bat him cleanup?

I haven't solved this one yet, but I still think that one lineup spot will make all the difference in games.  A pitcher has to bat somewhere, but I'd want to delay his departure as long as possible.  Pretty much every manager in history agrees.