I had the same thoughts about using Simmons' classification.  However, why do we apply a political boundary to Mexico's discoveries and not a geological one?

While not a geologist, I'd guess that the arc of the Gulf of Mexico is the correct vision of a province so that Spindletop in coastal Texas is the King and Canteralle and this new ones are queens and nobles.  It doesn't matter whether they have to be accessed from sea or shore.

What are the biggest fields discovered in Louisiana, Alabama, and Florida?  

Spindletop in Texas was not a particularly big field. Those were East Texas and Hugoton. Cantarell was pretty big, too.