One book on troubleshooting I read said, Go with your instincts just once and then systematically do the Sherlock Holmes thing if your instincts fail you.
I believe I try to keep instincts out of the troubleshooting process. But it is seductive.
While I cannot say your thought is not good practice, I do this out of courtesy to my customers generally. If I have walked onto hundreds of job sites and seen the same fault with the same piece of equipment, when I walk onto subsequent job sites with the same piece of equipment, exibiting the same malfunction, instead of charging those customers with several hours of labor for troubleshooting, I can only charge them with an hour or so of labor to go for the most common failure first. While yes, I do not make as much money on that initial job ticket not charging that labor, I do in the long run, as I have now have a more satisfied customer because their bill is more reasonable.