There is nothing "Mexican" about running wider tires on a 4x4. Now if I were running 13" 200 spoke daytons with a 10" backspacing I would agree with that statement. Its personal preference really. Do I think my 15" wide meats are better than a 10" version.. no because I am running thornbirds but I do think the added contact patch of said tire can benifit greatly when it comes to crawling and other general 4x4 shinanigans.

 

Your jeeps going to look sweet with those tires on it!

 

I dont think theres any question that 33x15.5s are going to wheel better than 33x10.50s or 12.50s unless you are talking about rain and ice on road performance. So long as the axles hold up on the trail.