While this (above) post means to be helpful, my experience has shown that there is little that any local (to the member) commander can do to hurry along with cases that are already forwarded to the PEB.
Now, there are commanders and there are commanders that have pull and are willing to dig in and apply pressure, so I am not saying that there can be no impact by commanders trying to speed things. (I had a client who was an 06 and a General Officer select who got a very fast outcome, a matter of weeks from MEB to Final PEB disposition....this Marine had people from the Commandant of the Marine Corps office checking in on the case. That is an outlier. The vast majority of times, there is next to nothing that outside questioning or pressure from the CoC can do to speed things along). My only point with this comment is that it is highly unlikely that anyone below a General Officer (and even then) can influence the speed of a case.
This is the rub. Sometimes cases are decided correctly and no attorney's efforts even matter. The MTF and MEB got it right. The PEB got it right. This is the ideal situation (and should ideally be the case for all members). I often say that a big problem I see is similar cases being treated differently. I see cases with very similar facts, and one member gets a great outcome and another gets a lousy outcome. This just confirms to me that the process is arbitrary and capricious and lacks controls to get the proper outcome in all cases.
That said, it's great that there was no need for additional help in Capybara's case. (Just a side note, I went on vacation about 5 years ago to the north central part of Colombia and at our hotel, there were a ton of capybara's running around...looked in size to be about 8-12 pounds and they were everywhere).