Not my place to judge how plausible the stories, although I will say this -- everyone should know a dilute test is a red flag, and that drinking lots of water could very well give you that result, so why would you put yourself in that position?
But no, it's not like Tunsil. Teams have to decide how important it is, compared to the talent level of the player.
As for your son, while I appreciate the kind words, that probably wouldn't work out.
Another good question.
Without knowing specifics, I think I'd probably put more on character.