Because these crews are some of the top crews across the state?
Because the coaches (who will never give up their option of picking the officials, no matter how much people whine, bitch, and moan) do their research and select the crews that they feel will do the best job for their game, with no preference given by the selected acres on who wins or loses.
You're giving an awful lot of credit to coaches here. They want officials that are going to benefit them, period. Every chapter, in the state has officials that are more than capable, and I'd go to bat for any official in this state that they can be objective and have enough integrity to not play favorites when officiating.
I've had a coach - who I believe is on a UIL committee, no less - tell me that if I want to be selected for a playoff game, I don't throw a flag against his team in a particular situation again (I was working his sideline.) It was a flag that I'd throw every time (LOS foul that was not even close.)
At the state meeting golf tournament this year, I heard with my own ears an official bragging that 'yeah, before the draft, my umpire talked to the coach and definitely got us the big Aldine vs ___ game.' (Yes, I know what team it was; no, I will not publicly say.)
Thinking that coaches don't abuse the current system, and that some officials game it too, is just being oblivious to the facts around you. And saying the system will never change, is defeatist as well. As long as we keep blindly accepting a tainted system that encourages corruption, it never will change. I will never ever stop criticizing the current process; the vast majority of the ones who defend it are the very ones who profit the most from it.