How important are landmarks of the thorax?

[Jedi of Zen]

How accurate do you have to be when locating the landmarks of the thorax (ie, in order to assess for tactile fremitus, percuss, and ascultate for lung sounds)? And when you're in clinicals (as well as in the real world of nursing, how often do you actually utilize those landmarks?

The reason I'm asking is because I have noticed that although our main textbook (Fundamentals of Nursing 6th ed, Potter & Perry) shows drawings of where the landmarks of the thorax are located, it says nothing about how to really locate them (either through palpation and/or through straight-up visual examination). In other words, it's one thing to look a drawing of several dots on a skeletal body, but I imagine it's a little different to be able to actually find those same precise spots on a real person.

I've checked all of my other textbooks, and it's pretty much the same story.

Also, my copy of Assessment Made Easy! (3rd ed, Lippincott Williams & Wilkins) has some of the said landmarks as being slightly different in location as well as in the total number of them. ie, my textbook shows 26 landmarks - 10 on the posterior, 4 on each lateral side, and 8 on the anterior; where as the Lippincott book shows 10 on the anterior, what looks like 18 on the posterior (I can't even tell for sure b/c some of the arrows in the picture look kind of funky), and none on the lateral side. And like the other books, the Lippincott has a couple of pictures that are sort of nice to look at, but the actual text itself (imo) says very little about how to accurately locate these landmarks.

So my question, again, is - how precise do the palpation/auscultation sites need to be on the thorax? And how many of them are there, exactly? Is palpation and auscultation on this region mainly just a matter of hitting up the general neighborhood of bronchial, brochovesicular, and vesicular areas? Or do you need to be more concerned with precise spots?

Thanks!

the Jedi.