For me, my primary emphasis is proper skill development. If a gymnast is very technically efficient and the skills are "easy" to them, then I don't think that there's a need to do a million routines.
Here in the U.S., our elite kids have to constantly be on their toes to be able to hit routines at a moment's instance because that's the philosophy of Marta Karolyi. I'm not sure if it's a trend that they started, but it's pretty much a mainstay philosophy in Romania in general.
In contrast, when the Soviets were leading the charge, they did a lot less routines and were far superior in terms of technique. So, their gymnasts not only hit their sets, but also were able to really "push the bar" in terms of advancing the sport with bigger, more innovative skills. Meanwhile, the Romanians performed (and continue even still today) pretty much cookie-cutter routines with mediocre technique - especially on bars.
If the Soviet Union had not been dismantled and were not suffering the current economic woes, I believe that they'd still be kicking everybody's butt. Of course, many of their top coaches have migrated to the West because of a better economic situation and way of life. So, their entire system has deteriorated dramatically.
As far as periodization is concerned, I haven't really done a lot on my own. I've worked under people much of the time and watched them screw it up. So, based on my career experiences, I'll offer what I'd do. Simply put, I'd pretty much follow general training principles with respect to volume and intensity. As intensity increases, then volume must decrease. I would define intensity as a progression from individual skills & drills (lower intensity) to doing parts/combinations (medium) to doing full sets onto competition landings (highest intensity). Volume would obviously indicate the number of reps of each skill/drill/combo/routine.
I'd say about 10-12 weeks from a competition, I'd start working more combinations while still spending time on refining old skills and doing drills/progressions for new ones. By about 4-6 weeks out, I'd start doing mostly combinations and a few full sets onto soft landings, with beam pads, etc. The last 2-3 weeks, I'd start doing more full sets onto real competition landings. In keeping with training theory, I'd actually raise the intensity the highest about two weeks out and then taper it the week of the meet so as to hopefully achieve the "supercompensation" effect.
Of course, at this point, if you'd done your job in developing the skills, success is really dependent more upon the mental side than probably the physical and technical.
As far as applying this across the course of an entire season...I'd decide which meets are important and which aren't. Then, follow the same protocol. Start easy and gradually build up. If the intensity gets too high, then pull it back and water-down for an unimportant meet to let the athlete recover both physically and mentally. Then, add back in the more difficult skills when it's time for the big competition.
Anyway, I don't think that it's rocket science. I think that general training theory can be applied very easily to be honest. I think that it's more a matter of coaches keeping their ego in check and not pushing gymnasts too quickly because of their own personal over-zealousness. Furthermore, I don't think that doing a million routines 52 weeks of the year is necessary if the gymnast has proper technical efficiency. At that point, the routines become easy and pretty much second-nature.
So, I guess the moral of the story from my perspective is to spend more time on proper technical prep and less on routines.
Just my two cents.