I'm in North Texas... What suburb/city are you refering to?
Let him play all sports as long as he can...Be aware, however, that there are those coaches that "prefer" your kid not play more than 1 sport...And keep in mind, that in Texas, you will have overlaps of seasons, so he will miss 2-3 weeks or more of practices, scrimmages, preseason games, etc. & if a team goes to post season (playoffs), coach of the next sport may likely sit him when he gets to the next sport.
Long about the sophomore year, it will become difficult to maintain all sports. He may one day be forced to choose.
Academics are another issue. In our 9-week grading periods, 2nd & 4th grading periods are usually packed with "projects", that usually take weeks to do. (English, Physics,(like trebuchets & Rube Goldberg (chain reaction experiments), History, etc.
Have to run...But a little food for thought.