I had no idea country fried steak was any kind of Mex. While I did live in Dallas for 3 years I was only under the impression that TexMex was a mixture of the two and never mistaken for authentic Mexican food. And yes there are plenty of authentic Mexican food in Dallas.
Country fried steak is Tex not Mex but it’s frequently found on Dallas “TEXmex” restaurant menus.
http://mattstexmex.com/MENU 2017 FRONT AND BACK.jpg
http://www.ojedasrestaurant.com/site/wp-content/uploads/2017/09/Ojedas-To-Go-Menu-2017.pdf
https://mattitos.com/menu/
Heck this one even has a chicken fried steak burrito
https://www.eltacoh.com/menu