For the Central Time teams (outside Nashville), eastern Texas is a more economically-feasible location for spring training than Arizona.
Take the Cubs for example. They currently train in Mesa, AZ, a suburb of Phoenix, and have done so for many years. The flight distance between Phoenix and Chicago is 1440 miles. I'm proposing the Cubs train in Fort Worth. The flight distance between Chicago and DFW is only 802 miles - and the time is the same between both cities, which are in the CTZ.
Did you think about this for more than two seconds? The Arizona setup is perfect. All teams in the Phoenix metro, great weather, good facilities. Everything they need and you're suggesting a bunch of teams now go to three different metro areas in Texas, all 200-300 miles and 3-4 hour bus rides apart from each other as a way to save costs?
Here's how it currently works.
Get a truck and send all equipment to Phoenix metro area. Team personnel and players make their way from whichever city they work/live in during the off season and make their arrangements to get to whichever city in the Phoenix metro area where their team plays.
The furthest stadiums in the Cactus League are Hohokam Stadium in Mesa and Surprise Stadium in Surprise. 45 minutes and miles from each other. Take the bus that morning, play the game and head back to your home stadium before the sun goes down. Quick, convenient. Works perfectly.
Now what you want is 8 of these teams to go to the Dallas metro, San Antonio metro and Houston metro areas, either take a long bus ride (players not happy) or a flight (owners not happy) and then spend a night (or several) at a hotel because it makes no sense to go 300 miles to play one game, get back on the plane/bus, go 300 miles home, play another game and continue that for a month.
Second, you have a couple teams playing at college baseball stadiums in the middle of college baseball season. That's not happening.
Lastly, these teams need more than one stadium. Look at any spring training facility. It's a stadium, several practice fields, training facilities, offices etc. Saying oh, here's a college stadium you can play at is totally insufficient and lacks any understanding of how spring training actually works and the facilities needed for it.