I think the main message that independently working on the same task can be a weak parallelization of random time tasks (independently random depending who is w

I think the main message that independently working on the same task can be a weak parallelization of random time tasks (independently random depending who is working on it). It simply falls in the category of "less than linear speed-up" parallelization. Since it is a trivial one, you can take it into account most of the time, however it's not too efficient.