I won't go so far as to say most Mexicans are over aggressive, if you see "over-aggressive" Mexican players I am going to tell you right now you simply aren't playing the right ones.
Another word of caution- Do not use online as a gauge of how good (or bad) the Mexican players are trust me I have played on GGPO recently and can tell you that it is not a good representation of what I see in person in Mexico.
While some may look overly aggressive on GGPO, believe me there are quite a few that know when to be patient and when to be aggressive. A lot of the patience I have now I learned while in Mexico, so just take what you see online with a grain of salt.
