Well, they have said they plan to make Sanchez and Lorenzen a tandem. Right now Sanchez looks like the better choice to start and for length, and one or the other of them could also be available out of the pen on their throw day (as Sanchez was yesterday). Maybe against a righty-heavy line-up Lorenzen goes first (or you name the starter to try and force the opposing manager to set one line-up or the other).
I think Suarez will still get a start over Sanchez in the playoffs but that doesn't mean he won't pitch in relief too. I don't know that you pick a Game 3 starter in advance anyway. Could also pick someone as possible NLDS Game 1 starter and leave them off the wild card roster.
Thomson finally admitted it out loud last night (that the 124 pitches may have been the issue. Still doesn't seem to have any regrets). But either way he has also never pitched this much or been a starter for very long. He could probably stand to miss a start and not come out of the bullpen either for a week. But not until after Monday alas.
I think the depth and optionality still made it a good trade, vs. just getting a pure reliever.