Whenever I am in doubt about anything to do with swimming I only seek advise from registered swimming or club officials. Trying to talk to various other parents only helps to deepen the mystery and increases the amount of rumours that are in circulation about things.
Be rational, take a factual approach, use measured results, calculate outcomes on proven criteria and make a decision on that basis rather than on emotional grounds or on information you heard somewhere.
If you talk a lot to moaners you’ll get mainly negative feedback, if you talk to officials they usually are supportive and positive.
One problem that often can exacerbate a situation is the fact that parents can sit and watch all swimming training and sometimes feel bad about something. The biggest mistake a parent can make is to go on those emotions and have a word with the coach, who is just trying to conduct the lesson.
In schools, parents are not in the classroom and cannot watch the lessons, parents act on what they heard from children and need to talk to teachers after the lessons or to head-teachers upon appointments.
Try to use a distant approach with swimming coaches; just because you can see them all the time doesn’t mean you can approach them all the time whenever you feel like it. This is counter-productive.
The only time I approached coaches is when I could proof my point.
For example in swimming clubs kids get promoted to squads and usually their time is the trigger factor for promotion. I noticed that a coach promoted other swimmers despite my swimmer having had faster times in competitions. I complained about this and made a good impression and gotten the result I wanted.