Their incentives cannot be completely aligned by definition. One views you instrumentally, the other doesn't. But it can be difficult to tell because, as you point out, there can be some alignment and even some truth in the advice of persons who want to exploit your ability. This is why I suggest erring toward taking advice from the dead. This has the virtue of being the most disinterested advice. It takes experience to follow advice from the living. Most of this is noise. Look for alignment with the advice of the dead, especially if this has withstood the test of time. You should note that my attempt to defend my advice from criticism is already validating my thesis, which is that you should not take my advice until after I am dead, and that goes double for my contemporaries.