In a word: Yes.

If you're really interested in how to, um, correct most vendors' attempts to create an effective node set-up, then there are a few things you can do:

• Read around on other CG discussion boards, especially the more "pro" ones. Yes, there's a whole bunch of stuff that will be beyond your experience AND will not apply to Poser, but you'll also become familiar with the bits that are. And maybe pick up some things that, later, you'll go "Aha! I remember reading about such-and-such!" and you'll have a better idea where to start investigating a particular feature.
• Don't be afraid of learning how to implement some basic arithmetic using Poser nodes. It's incredibly simple once you work out what's going on. Many proper materials require that one value be the inverse of the other. Learn how to do this using Poser nodes (well... just one for a straightforward inverse function) so that you can do it in your sleep.
• Learn some elementary physics about how light interacts with surfaces. Stuff such as how reflections are tinted depending on the property of the material they're bouncing off. (This will allow you to correct a large amount of shaders where the vendor/whoever has plugged a diffuse colour map into the specularity colour... some materials require it, other materials need only white in the spec. colour, for example. Knowing which is which will help your materials look better.)
• Read the materials threads here and in the Node Cult on the RDNA forum. Especially those posts by Bagginsbill where he explains in detail what one of his materials is doing and why (the "why" can then be taken and used for other materials you want to try).
• Don't be afraid to try things and then ask questions about the results (here or at RDNA) if they're not as you predicted they'd turn out.

EDIT: Please don't disregard my reply, though! I typed it up and pressed "Post" and everything!