I’ve had good luck hiring contractors for Haskell related problems for much the same reason that hiring full time engineers to work with Haskell has gone well: the average quality of Haskell developers is high, and there are more people who want to work with Haskell than there are opportunities.

That probably wouldn’t scale up if you were hiring many tens or hundred of contractors. My experience with that degree of outsourcing hasn’t been positive irrespective of language though.