On some worlds masses of SDBs sit in well-dispersed hardened hangers
with their highly-trained crews right by them even in complete peace. On
others a few old worn-out SDBs sit at the world's main port, most of
them in no fit state for space, their crews dispersed around the port
city on half-pay, working other jobs to make ends meet, or passed out
drunk in some alley.
You've just described the difference between "civilized" and "barbarian" worlds in David Drake's RCN (Royal Cinnabar Navy) series, which (with the exception of the way "jump" works) is a very good approximation of what MTU looks like along the Imperial fringe.
Well, I take that back. The "civilized" worlds tend to be penny-pinching oligarchies, so those "highly-trained" crews tend to be put on half-pay and most ships "laid up in ordinary" within a few weeks of peace breaking out.
Lt (later Cpt) Leary tends to be the exception to this rule, spending his own money to take the Princess Cecile into private service as an armed yacht and running about as a one-ship troubleshooting concern. In other words, the perfect PC. :)