You cannot know who is the real expert... Is there one even? You hear a thing here, read a thing there and then you try it out and form your own opinion.
And somehow almost everybody in this game thinks, that his way of doing things is the only right one.
But we both know, that this isn't true.
So basically all I wanted to say is, try out stuff yourself. What I said above was also just my opinion, that these things doesn't really matter in my eyes and that your expert will also just passed his own opinions and experience to you, which can be somewhat true, but doesn't have to be.
Plus the other topic was about the manipulators... I don't have anything against them, I tried it out myself before. But just because someone has a huge trophy cabinet and an insane winning record, it doesn't necessarily mean he is one of the best managers. In fact the hardest-to-beat and most respectable managers I know, are the ones with also good records, but not those perfect ones.
At the end it's just about taking the good stuff from every mentor you might meet and develop your own strategy. It's what I did and it really helped me on my way! I wouldn't consider myself as one of the best managers, but I am happy with where my knowledge is now compared to a few years ago and always learning more.