Brett, Louis is certainly right that I would be the last person to accuse you of "over-analysis." Actually, I think we are often guilty of "under-analysis" when we casually accept notions about the things that popular flies are said to imitate.
Personally, I find it useful to think of a trout's prey as typically fitting into three broad and somewhat indefinite categories--unfamiliar potential prey, familiar abundant prey, and temporarily superabundant prey.
The first category covers things that a trout in a general feeding mode is usually willing to sample. Most of the time, flies that we label as "generic," "attractive," or "suggestive" fall into this category. This group includes some of the most famous, versatile, and broadly successful flies ever devised. I would certainly include flies like the Wooly Bugger and Royal Wulff in this category. (Most of the time.)
The second category includes prey items that the trout encounters on a regular basis. Flies in this category provoke specific recognition by the trout, even though this may not be an exclusive focus. Fairly accurate imitations of prey items like scuds, cressbugs, midge and caddisfly larvae, minnows, aquatic earthworms, etc. fit into this group. These are specifically imitative "searching" flies, and their value when compared to the more broadly suggestive flies in the first category depends upon the relative abundance of a prey form. This can be specific to a particular stream or (especially) to concentrations around a particular trout's lie. On food-poor streams, the significance of this category is often diminished, and "attractive" or "drawing" qualities of first category flies may provide an edge.
The "superabundant" category includes specific imitations of heavy hatches or of any other prey that temporarily overwhelms other food forms in abundance. This can be due to emergence or egg-laying activity, or due to such things as concentrated behavioral drift or seasonal migrations. Most of our "hatch-matching" efforts are (or should be) focused on these prey items. Not every hatch provides sufficient quantities to warrant this specific attention from the angler or the trout. But, to me, these opportunities are among the most fascinating (and often, the most productive) times to be fly fishing for trout.
To be sure, some flies can move freely among the different categories at times, and what fools one trout (even within a particular category) won't necessarily fool another. I do think, however, that keeping these broad categories in mind can help to make sense of situations astream and can be an aid to more effective fly selection.