OK, since it's an interesting story, i'll play –
>Who were the Modelo Group?
This witch and her family. Grandfather was founder - Basque immigrant to Mexico. 6th richest person in Mexico.
https://en.wikipedia.org/wiki/María_Asunción_Aramburuzabala
>Who are the Modelo Group?
As of 2013, Anheuser-Busch InBev SA/NV based out of Belgium.
https://en.wikipedia.org/wiki/Anheuser-Busch_InBev#Grupo_Modelo
>How tied to CB?
CB got the US rights to Modelo's brands (Corona, etc.) in a settlement with the DOJ to allow the merger.
>Where is the facility located?
Nava, Mexico right on the southern border of the U.S. Closest city-San Antonio TX. Ground zero for the current border crisis.
They also built a new brewery in Mexicali, close to California.
https://www.beeradvocate.com/community/threads/constellation-brands-to-build-new-10-million-hectoliter-brewery-in-mexicali-mexico.373898/
>What major dynasty is connected to this region?
No idea, but the PRI (Salinas) has been running the state of Coahuila since forever. The Gulf cartel & Los Zeta control the human smuggling/drug trade.
http://www.borderlandbeat.com/2012/11/the-zeta-control-of-coahuila.html
>Garza, railroads, Modelo.
Garza I assume is Tony Garza, the witch's ex-husband. Texas RR Commissioner from 1999-2002 and US Ambassador to Mexico under GWB.
https://en.wikipedia.org/wiki/Tony_Garza
From the beeradvocate article above, CB is transporting all their beer into the U.S. by rail.
See where this could be headed, but as of right now, this is all legitimate business operations.