Tim's post reminded me of how, let's say, multi-faceted this discussion is. One example: as with my fairly modern set of 14 clubs, why wouldn't I drop -- without missing a single thing/scoring opportunity -- the 3 wood and the 5 woods, and replace them with a "4" wood? My Ping G2 so-called "5" wood is 17 degrees (!) and has a stock shaft that's actually longer than my older-model 15 degree 3 wood and a degree stronger than my 18 degree 2 hybrid/5 wood. Now, sure, it would be nice to have the 2 hybrid for the occasional long Par 3, but if I want I can now have a 3 iron (see chart below) that's 20 degrees, or, if I've got issues with 3 irons, a 4 iron with 23 degrees. Heck, I could play with nothing more than a modern, 30 degree 6 iron and (because of the longer shafts) basically have my traditional 4 iron thrown in there for free. Manufacturers have obviously squeezed several long irons into one tiny window/gap precisely because it leads to a 46 (or 45 or 43 degree) PW, and thus 'necessitates' a gap wedge and another and another. So if someone suggests that in their half-set they go driver, 4 wood, 4-6-8-PW-SW-putter, they may not actually be crazy (or just effing around not caring about score).
Ah, alas the chart didn't show up as I cut and pasted it, but all scrambled instead. I hope you trust me...