the fighting to start, smokey, rattly diesel engine problem is usually bad adjustments not problems that are voodoo.
Diesel engines are very very tough and durable, but require a level headed driver, meaning do not start and go out full rpm driving unless the engine is at normal temperature and stabilized.
By your statement it seems that your idea of maintenance is flawed, let me give you an example, if you have a Ariston or Indesit Front load full automatic washing machine and appoint a gali ki dukaan handyman to fix it who does not know its working intricacies - do not expect for it to last long.
Or if you have a meat locker that cannot control subcooling as per spec and get zabardast AC karigar to fix it who does not vacuum the system or does not pay attention to gas load by subcooling and superheat to fine tune the unit, Dont expect the meat locker to 'freeze' meat.