I guess the idea is to not disrupt the middle of the lineup while Travis is out (though that's probably going to be for awhile). This whole belief in fixed lineup spots (and rigid bullpen roles) is all very Cito Gaston like. Gibbons used to run different lineups practically every day in the old days.
Pillar seems to be the only want who wants it. The middle of the order hitters want to be middle of the order hitters. It's a baseball culture thing and not really a battle worth fighting.
Norris and Estrada were battling it out for the last spot last year. Sanchez was in the mix too but he was bumped to 4th starter after the Stroman injury.
It doesn't make sense to be opposed to this without even knowing what the terms will be. Nothing wrong with negotiating with a player with a stated interest to stay. You can always walk away if you don't come to terms but I suspect they'll find something that works for everyone.
Would you say the Lind trade was stupid because Estrada was put in the bullpen (which he was)? Chavez's value as a guy who can make starts doesn't disappear if he starts the season in the bullpen. That won't determine whether or not it was a stupid trade.
Last year IIRC we had three guy vying for two spots (Norris, Sanchez and Estrada). This year, Estrada has basically traded places with Hutch on the depth chart and there are 4 guys (Chavez, Sanchez, Danks, Hutch) competing for only one spot.
I thinks Saunders' performance is what's important. If he looks healthy, he gives you the option of holding back Pompey as a plan B in AAA until the inevitable callup.