Bill Cody and TJ (teehjaeh57) are smallmouth experts and will see this at some point and give you some solid advice.
What I can tell you is smallies can definitely survive, and thrive, in southern waters. However, if largemouth are already present, they will outcompete any smallies you add to the mix. Many factors for this. Largemouth can simply eat more than smallies due to their larger mouth gape, have a higher fecundity and I would imagine habitat would also play in their favor too, in Texas.
