It isn't rotation between jobs.
It is that the surgeon or the pilot does more than surgery or flying.
This should not be very hard to imagne at all. I am told pilots actually have a very short work scheduel, spend a lot of time off. I think we can be confident that during that time off they sometimes are doing very rote things. Doesn't interfere.
The notion that a surgeon can do surgery and play golf -- or administer the dept, or hassle nurses, etc. etc. but that a surgeon cannot do surgery but also do other tasks so the sum total is a balanced job complex, eludes me.
The people who do task x must, you are correct, be able to do a good job at task x. Whatever we may be talking about.
Instead of people doing a homogenous combination of tasks all of comparable quality of life and empowerment implications -- higher or lower on the scale -- coordinator class or working class -- we have, in parecon, people doing a combination of tasks that have roughly average empowerment and quality of life implications.
This not only does not imply that you do things which you are inequipped to do -- it says that 80% of the population, rather than going through class division producing socialization and education dumbing them down to have neither expectations nor confidence, nor skills to participate in empowering tasks -- have, instead, their fullest capacities addressed and developed.
The gain is enormous -- unless one thinks, of course, that the reason why working those who do rote and obedient tedious labor (and even why work is de-skilled intentionally to have those attribtues for most people) is because most people, regardless of upbring, education, and on the job conditions, could do not do anything more empowering.
But I would say that would be a horrendously racist, sexist, and classist view ...