For what it's worth, I consider oil to be closer to a unixy PowerShell rather than a more powerful bash. Note that this is not a slight, PowerShell is sweet for what it is. It (oil) really takes a hard left from the POSIX philosophy of focusing on one thing and doing it well. I'm also bitter that, if it's going to veer so far away from POSIX, that it didn't go the whole hundred and become a function language with comprehensions and such.
For what it's worth, everything you mentioned above about your approach can be done with parallel.