Here is an excerpt from Robin Emmott's article on Reuters.com:
"Mexico's Gulf cartel and its brutal "Zetas" hit squad are taking on the country's most wanted drug lord on his own turf, escalating a fight for supremacy in a drug war that is worrying the United States. The Zetas, considered Mexico's most violent gang and feared for beheading victims, are pushing into the northwestern state of Durango in a new battle against arch-rival Joaquin "Shorty" Guzman, Mexico's top drug fugitive. At least 235 people have died in drug violence in the mountainous state this year in a fight over smuggling routes and marijuana and opium plantations that Guzman has long dominated... "Without a doubt, the Zetas are advancing in Durango and some towns are basically under their control," said Rafael Herrera, a political analyst and former editor of a regional newspaper... Lazcano is turning his attention in Durango to controlling rural outposts along smuggling corridors previously held by Guzman to win informants, hide and attack the military." Link to Full Article
Analysis: There is no doubt that the level of violence in Durango has increased in recent months, as documented by Ms. Emmott in another Reuters article. When violence increases in a relatively specific area in Mexico, that means that either two DTOs are fighting for control of a lucrative plaza (a drug smuggling corridor) like Nuevo Laredo or Cuidad Juarez, or a DTO is having some internal control issues, like the AFO in Tijuana. I also have no doubt that some sort of conflict is going on between the Sinaloa Federation and Los Zetas. My question is what Lazcano's priorities are with this strategy. The article mentions controlling outposts along smuggling routes, winning informants, finding places to hide and attack the military, etc. However, those are lofty goals if he expects to accomplish all of them.
Let's do a quick comparison of Los Zetas and the Sinaloa Federation, while making a few assumptions. Los Zetas used to be merely enforcers for the Gulf cartel, but after Osiel Cardenas Guillen was incarcerated and extradited to the US, they took over a good chunk of the Gulf cartel's operations. While I don't think anyone is ready to say that the two organizations are one and the same or use the names interchangeably, one can reasonably assume that any moves by Los Zetas has a direct impact on Gulf business, for better or for worse. There are two important differences between the Gulf and Sinaloa cartels. The Gulf cartel controls more plazas than the Federation. However, the Federation controls significantly more physical territory than the Gulf cartel. Controlling more routes is a competitive advantage because you can move more product across the border. However, controlling more territory has the advantages of providing more places to manufacture drugs, more places to hide, more officials to bribe in population centers, and more potential recruits.
I'm sure all of the Sinaloa advantages are tempting to Lazcano and his crew, but El Chapo is quite a force to contend with. He has his own enforcement teams, Los Pelones and Los Negros among them. No one really knows the exact Zetas numbers, but the latest estimates place them between 200-250 core members. However, Los Zetas have grown into a network and almost a brand name; that network of informants and other associates could number in the thousands. This would serve as a huge benefit to Lazcano in a conflict with El Chapo's people. Undoubtedly, El Chapo has a challenge on his hands. Not only does he have Lazcano to worry about on one side, but he's also backing Teodoro "El Teo" Garcia Simental in a battle for AFO's remaining territory in northern Baja California. As is typical for these kinds of turf wars, things are likely to get worse before they get better, and as the author implies, only time will tell who has the upper hand.

