Well, that in itself could be a problem as
1) The Three Callabros took place in South America not Mexico, Argentina I believe
2) Adding characters to talk about the country in my mind would be even more disrespectful to the people of Mexico and the general public, my feeling toward all of Epcot and charters is that they should be void with the only exception of finding the original WS Characters except (American Mickey, Norwegian Goofy etc.) Other wise you are pandering the public with characters they already know but may not really fit, new more representative characters should be created like Figment and DreamFinder. Epcot is to educate and to experience, there are awe-inspiring means to convey these ideals with out the use of pre made characters