If the foreign candidates were so much superior than locally born candidates as you explained, why not just open a campus in that country and thus save the best employees from having to uproot from their native culture?
I think the real reason for hiring locally is both that communication works better, and that the higher ups don't want to give the impression that their jobs could also be outsourced.
But, for existing teams they wanted (reasonably) to avoid splitting between locations. So you need someone local.