I have been a tech for 40 yrs. Worked on most everything out there in my time. IMHO I feel your right about electric techs having to change a little to work on I.C. trucks. There are also some areas in any country where electric trucks are few and I.C. is king. Techs in those areas, I bet would not have a problem working on the C-5.
Being an old Clark guy, I compare the C-5 engine to the C-500 engine. Derived from a diesel with balancers, etc. But with all the new electronics of todays emission standards.