At our school, we have a written policy on "play time." This is given to the coaches as well as all the parents. The policy explicitly states that play time is up to the discretion of the coach(es), and that parents are not allowed to have any discussion about playtime with the coach, AD, etc. This policy came from the AD and VP in charge of sports, who used to be a coach at the school.
This means that as a coach, I could only enter my best kids into meets for an entire year and have my slower kids never go to a single meet and according to the policy, the AD would refuse to listen to any complaints over this issue.
Obviously I wouldn't do that, and I've never met a coach would would do that. In track, we have the liberty of throwing our slow kids into meets and all it costs is a few bucks, there is no risk of losing a meet because of that.
At our school, we put every kid into the dual/tri meets, every kid who works hard in practice into at least one or two invites, and our fastest kids get put into more invites. Every kid is entered into the league championship meet (and can therefore qualify for the sectional and state meets if they run fast enough.).
Kids who don't work hard in practice only get to run in dual/tri meets. Kids who skip practices for any reason other than doctors appointment, a specific academic need, etc are left out of every meet including even our dual/tri meets.
As far as I know, we've never had a parent attempt to complain in the 4 years I've been here.
I think your AD's policy is absurd. It doesn't support any of the life lessons or overall learning goals I can think of for high school sports.