[lptk]

> but parallelism is also a base fact of many problem domains, where you have multiple agents (up to and including humans) collaborating and interacting simultaneously.

I don't think parallelism is the word for that. More like concurrency

Parallel computing is closely related to concurrent computing—they are frequently used together, and often conflated, though the two are distinct: it is possible to have parallelism without concurrency (such as bit-level parallelism), and concurrency without parallelism (such as multitasking by time-sharing on a single-core CPU).[5][6] In parallel computing, a computational task is typically broken down into several, often many, very similar sub-tasks that can be processed independently and whose results are combined afterwards, upon completion. In contrast, in concurrent computing, the various processes often do not address related tasks; when they do, as is typical in distributed computing, the separate tasks may have a varied nature and often require some inter-process communication during execution.

https://en.wikipedia.org/wiki/Parallel_computing

What you're describing sounds like it would be solved by primitives such as the actor model, not by Haskell-style FP.