I just helped a friend out by reviewing a site that he's now the Webmaster for and he thanked me for doing such a thorough job. I couldn't help but think of it like when I was young and working for my father. Whenever we pulled an orchard out, we had to prepare the field for whatever crop would come next.
Of course, with something like a cherry orchard, you can't just plant trees the next year, you have to let the field lie dormant for a while to recoup nutrients. One of the things you need to do before planting another crop is to "pick up rocks." What does that entail? Well, you need to have a tractor and trailer and at least three people: one to drive the tractor and the other two to literally pick up those rocks that are too big to be left in the field. What qualifies as too big? Anything you can get your hands around, that's for sure. Sometimes, as you're walking along, you see something that looks tiny. As you get closer, you get the feeling that it's bigger than you think so you start brushing dirt away from it. Often, something that looks like a paperweight turns out to be a big, unwieldy, forty-pound monster that you need to get help with and that's why it's good to at least try to turn over every stone.
In that same way, you can look at something on a website that looks like it's easy to change from a structure perspective but as you more closely examine it, you see that changing it will have broader consequences than you realized. Even still, it's wise to "leave no stone unturned" regarding the information structure of a website in order to explore how better to serve your audience.