All of the pilots that Sunwing has "hired" are Canadian citizens. The foreign pilots flying for them are here on temporary deployments as part of their reciprocal aircraft sharing agreements. Same goes for Canjet and Skyservice. They aren't giving permanent employment to any foreign crewmembers.
J.O. - sorry to report, but CanJet DOES NOT have a reciprocal agreement when they bring foreign pilots into Canada. And Sunwing's reciprocity barely meets the definition.
Reciprocity works when it's legitimized through written agreements and quotas. Otherwise it's just a "free for all". And that is not good for the profession no matter what country you're from.