Sourcing cocaine from the Mexicans seems like a North American thing. Even the majority of the non-Italian European OC groups that are deep in the cocaine trade like the Albanians, Irish, British, Dutch, Serbs/Montenegrins, Moroccans, Turks...have a direct link to Colombian suppliers.

Some who don't directly source from the Colombians have links to the Dominicans since Dominican networks are important middlemen between Colombian groups and others. Dennis G. (a Dutch business associate of Taghi) for instance was arrested in the Dominican Republic. Several other Dutch drug trafficking networks use their links to Suriname or Curaçao since networks in those regions are also notable middlemen for the Dutch market.

In general though, there's a prevalence of direct Colombian links to source from. One Albanian clan from instance set up shop in Ecuador and a Serbian group set up shop in Peru. In both cases the groups did business with affiliates of the Urabeños/Clan del Golfo, arguably the biggest Colombian drug trafficking organization at the moment.
In Antwerp, for some time the Y. group (members of a large Turkish-Assyrian clan) and the Eleftherios P. group (a well known Greek cocaine trafficker based in Antwerp) brought in so many tons from Colombia, the Antwerp authorities suggested an intense cooperation with Colombian authorities.

One of the few cases of the cocaine trade in Europe where a high level criminal organization from Europe was sourcing from the Mexicans was when a Liverpool-based outfit (the guys from the Speke district) was doing business with the either Sinaloa or the Zetas. Though cases like that are few and far between compared to how many times a Colombian link is detected.