Who would you rather they play than Marsh and Stott, both of whom are elite defenders? A little more Sosa is fine, and Hays was already playing, so Stevenson and Wilson will pick up some of that. But that's as far as it needs to go.
And Marte has not spent much time in the majors at all this year. He's fungible, and won't last much longer in any case (he probably gets sent down for Walker Tuesday).
Walker is still probably better than Allard. He is still going to be on a short leash, and in a diminished role. It remains in the Phillies' interest to get some useful innings out of him as a starter as well as to see if he can put this whole season behind him and come back next year. If not, he's done, and I doubt he pitches a meaningful October inning anyway (again).
In the meantime the next inflection point would be Suarez's return. Do they go to a six-man then (Thomson sounded doubtful in his latest comments), does Phillips lose his job to Walker just like Turnbull before him, or will Walker pitch himself out of the rotation quickly?