Texas reps make their goals simply on population growth in those territories alone. That is the same reason why other metro areas around the country do so well too. Has zero to do with sales talent, and everything to do with territory demographics.
Treating all territories the same is a LAZY management approach to goal setting and sales force management. Once in a while you will get a good manager that can analyze the statistics and set goals in a fair and equitable fashion across a district, region, or even country, but that is rare; especially in the pharma industry, where most people moving on to management get promoted way too quickly - before they ever get the experience working a difficult territory. On the other hand, they may simply be bad people that do not give a damn, and will eventurally die miserable and alone, but by then it is to late for all those that suffered under their pathetic corrupt lifestyle.