The issue with this train of thinking is you forget that while you are absolutely right. Issues in a 10yo tank can be vastly different than a 2 month old tank. The reefer who has the 10yo tank more than likely had to deal with the same, or similar issues the 2 month tank owner is experiencing with there own tank. And they found a way to resolve those issues that then lead to a successful reef 10 years down the road. They then can share what happened to work for them to lead to such a successful tank so many years later.
Someone who has had a tank for 4 months and beaten back the issues of a 2 month tank, still only has 4 months under there belt and can't really speak for long term success with even the method they used to resolve the issue. Who knows in another month the 4 month tank might be right back to where the 2 month tank is, maybe that reefer then gave up at that point. It's hard to say the success of a particular methodology in solving an issue when there is no long term evidence it worked..
Edit, your analogy doesn't really relate here either. A better analogy to the situation at hand using your exmple would be who would you trust more to teach your 16yo how to drive, an 18yo or a driving instructor?
JMO ofcourse
I do completely agree that someone with 4 months experience can certainly still be more than helpful to someone at the 2 month stage than no one atall. And I'm not saying that because they only have 4 months experience they shouldn't be helping out. Just that they only help with things they have only experienced for themselves or by directing someone they may know has knowledge on a particular topic. There are better ways to help than just parroting something they read somewhere without having any personal experience with that they are talking about.