Clemens is not going to play himself into a starting LF job anymore than Sosa is going to Wally Pipp Turner. No need to make him into more than what he already is, an occasional starter and PH. He just needs to have LF in that quiver once Turner is back. More likely than not he will still get optioned temporarily (and play LF in AAA).
Playing Merrifield or Clemens regularly in LF and Marsh regularly in CF just makes the defense that much worse, and without the likely offensive payoff (Merrifield clearly doesn't have it anymore, and Clemens would likely not provide it playing every day).
More "'good problems to have." I still think the ultimate answer is trading Pache and cutting Merrifield, with Clemens and TBD replacing them, but that is probably still two months away. Demoting Rojas in the meantime still an option but I think that is more likely to end his MLB season, not be a 4-6 week reset. Since the team's results still speak for themselves, why change anything (though that's also the reason to figure out how to keep Clemens up).