I cannot say for sure, but I don't think lobos and cobras are the same. The phrase "cobra o lobo" started appearing around 2008 in connection with protected witness statements explaining the structure of los Zetas, and especially what types an estaca consists of. I think it has been lost in translation, or perhaps lost in the copycat Mexican press. It is supposed to be referred to in PGR/SIEDO/UEIDCS/014/2007, which don't seem to be accessible anymore.
It could easily have meant that either a cobra or a lobo was present in an estaca, not that they are the same. Or it could have meant a "civilian". Cobra does not necessarily mean "Cobra, the type of snake-group", just hired gun, derived from the verb cobrar.
What is for certain is that Los Lobos started to appear in news outlets around 2003 and that known Nuevo Laredo gang members from previous independent organizations like Flores Soto, Medina Ortiz and Los Tejas were incorporated into the organization. Los Zetas integrated some members from Los Lobos, but then again, so did they from Los Tangos.
I think it thrived well under Meme Flores leadership. He was supposedly much liked by both Osiel Cardenas and Lazca. It probably started to go sideways when Meme Flores was arrested in 2008 and Karis took over. Being the brother of El Cara Muela, previously driven out of Reynosa by El Hummer, and becoming a group of both distrust in the rift between Los Zetas and Tony Tormenta, and a recruiting ground, I can see how it got absolved. However, Karis is very much revered in Matamoros and they still have a Grupo L there from what I understand.
Around midnight the Facebook page "Reynosa Codigo Rojo" published the following:
"'El comandante panilo' just yesterday killed 'el comandante cococho' of the people of 'el negrito' and today killed other 'estacas' of choco and jessi who are aligning with another cartel at his command he has more than 100 vehicles and they are going out against choco metro 90 and Guero yessi and all the 'achichincles' for being traitors try not to go out during the weekend and especially to clubs there will be a 'limpia' there will be gong about the people of 'panilo' 'el gato' the second in command of 'panilo' already has orders today before dawn the hunt began"
On a side note, the page also talks about the location of "El Pelochas", so he apparently was not killed as previously rumored.