"Who will do the essential but non-career enhancing jobs?"
Historically, thats always been the dubious pleasure - nay, the raison d'etre, even - of the non-commissioned/oik side of the house...
The "9 yrs to get to the next rank or GTFO" has been a pleasure known to them for years. Granted they then get 13 years to get to Sgt or GTFO, then another 7 to Flt Sgt or GTFO and so on... but the principle remains the same.
Or rather they used to when I was in...
Then again, considering how many of 'em are being outsourced to BAe or Serco/made redundant in order to create McJobs to keep the local knuckle draggers/sorry, Labour voting client state/Civil servants off the dole, maybe these pleasures will then fall into their laps instead...