I can tell you for a fact, at least from my experience, that there is no difference between a person who has a degree from a university outside of Argentina and a person who has one from a university in Argentina. I've been working at companies here for several years and have been involved with hiring at different times. Not once has anyone ever been hired because of that factor.
These are the things that will make you stand out and endure in an Argentine company, in order of importance:
1) Bilingual North American English / Spanish (any kind) - and I mean REALLY bilingual, speak read write and HARD TO FIND
2) The ability to get along with your colleagues and understand Argentine culture - they like the fact that you are different- but they don't want to you be an "outsider", don't say anything overtly negative about Argentina, even if they do - it's their country, embrace the culture, learn the national anthem, know the meaning of 25 de Mayo, 9 de Julio, know who Belgrano, San Martin, Sarmiento, Perón, Spinetta were, when they lived and what they did.
3) Know your foods - churrasco, milanesa a caballo, fugazetta, papas provencal, fainá, tinto con soda, etc.
4) Don't constantly compare your country to theirs
5) Know how to laugh at yourself
6) Be a gentleman to the ladies / and a lady to the gentlemen
7) If you are invited to someone's house, make sure you go, and there may be times you can't but don't reject every invitation - if people invite you they REALLY want you to come and enjoy some time with them and their families
8) Know something about football and it's terminology - hincha, xeneize, golazo, arquero, empate, know who Martin Palermo, Diego Maradona, Lionel Messi and the major teams are - Boca, River, Independiente, Racing, etc.
Follow this and you'll be long term at any company.......