I don't think this idea of 'every club in the bag' should be artifically put into a design. If it happens, great. But if not, just go with it. Many times, not all shots will fit into a certain design. I think if anything, the current design of courses, and equipment, etc., is more forcing the long iron play out of the game far more than it is forcing out mid-iron play. I have openly wondered if Ben Hogan would have been the great long iron player he was if he played today.
As far as guys on the tour go, they are hitting drives, many of them, and especially the ones on TV all the time, in the range of 300+ yards. So, on a 450 hole, that becomes D-9 iron or even wedge. I mean, if you want those guys to hit 5 iron into a par 4, without some kind of obstacle to shorten the drive or force them to hit a club other than driver off the tee, the hole needs to be 510ish yards long. And that 510 assumes no altitude, a general lack of wind, and so on. You can't really design courses for those guys out there. The level and quality of play among those few is so much more advanced than just about anyone else who will play the course. The vast majority of golfers who play a given course will hit all 14 clubs in the bag.