COPA Airlines interviews
I heard that the "problem" with pilots from Argentina was the same of pilots from Brazil : many pilots got hired in the past and then left few time later!
Now probably it has changed a little cos they re hiring Brazilians and Argentinians!
Just a personal opinion: Portunhol is not a issue, portuguese speakers are able to communicate in spanish after 2 or 3 months!
Fly safe guys!