The real test for a strength coach should be if he can a very good sportsman and make him great, or if he can take a great sportsman that has grown stagnant, and make them great again. If he can do either of those things, then it is money well spent.
That being said, if you see a guy with weak credentials come out of nowhere, and suddenly he's in demand, 10 out of ten, he's a connected drug guru, nothing more.