I invite your expert opinions on this subject: "important differences between the laws of the English speaking countries of the world and from the Latin American countries, better phrased as "The differences between "Common Law" and "Civil Law"

Please confirm if my understanding is correct. . .

I understand the following from my experience working in Mexico and Latin America.. 

case 1. A consumer goods manufacturer from another country gives a non-exclsuive agency agreement to a distributor in any country in LAtin America (my personal experience is of Guatemala) just the fact that the distributor has a non-exclusive agreement entitles the distributor exclusively to import the manufacturers product in that country. ., as per local laws  the manufacturer is estopped from supplying to any other distributor his products. .

is my understanding correct? does this also hold true for Mexico and other Latin American Countries.. ?

this is not the case in Common law countries where the contract strictly lays down what rights are given to the distributor as opposed to the civil law situation in Latin America where the law of the land grants to the distributor certain rights and privileges which are not offered in the contract.. 

Case no. 2.  Mexico at the current moment of pandemic. . INDRE (Mexico) any Mexican individual or company importing PCR test kits and submitting these kits to INDRE for approval is granted a provisional approval which is called "Registro en blanco" just this application by a Mexican company grants to the applicant exclusive right to import this product into mexico.. , even if they have no contract whatsoever with the manufacturer .. .  is my understanding correct. . ? this is differnt to common law jurisdictions where the contract spells out the rights and liabilities and is enforced. what laws in mexico govern these aspects. .

this will be a very interesting topic for lawyers as well as non-lawyers our students to know about the difference in concepts between Common law and Civil Law (   https://en.wikipedia.org/wiki/List_of_national_legal_systems#/media...  )  ,

what other notable such differences can you enlist about privileges or liabilities under civil law which are different from common law jurisdictions . ..