The biggest problem with hiring temps or gig employees for anything that requires higher intellect or training, is that while occasionally there may be the few astute, quick studies in the group, most are below average in performance and errors quickly build up in production. If these workers were good, they would already have full-time jobs. Managers are unable to get to know the strengths and weaknesses of their temporary charges on such a short term basis, so while it may look like lots of work was done, don't look too closely, because buried in there is a mess which will be costly in the end.