Look, we really are getting to the point where we're just arguing over how many Trotsky's can dance on teh head of an ice-pick::To be sure, that passage does not address the detail division of labor
needed to sustain socialist abundance. However, it does firmly advocate
job rotation.
I have *never* argued against people freely changing jobs, my *sole* argument has been against an enforced and proscribed rotation, i.e. my assertion is simply that such interplay of jobs will occur organicaly, out of social necessity.
Further, I would hold that there would have to be responsible agencies, co-operative structures, which set out to perform specific productive tasks, such as shoe production, etc. and I think that people will be members of such organisations, performing myriad actual tasks within and for them - at the very least, certain regions will have a local productive speciality based on geography, which in a world-wide system is a social division of labour.