Wear and tear? Not sure what you mean by that.

If wanted certain gearing for flatland racing, then going into the mountains to race, I would personally do the following.

1. I would have a standard 53/39 and compact 50/34 crankset ready to go.
2. I would also have a 12/25 cassette. Those are good for all around use. I would also have an 11/23 standing by for those races with a whole range of terrain.
3. I would also have a couple chains, each at differant lengths to compensate for differance in slack when swapping between cranks.
4. I would have one standard and one compact front der. Both braze-on.
5. If my frame was not braze-on, I would also use a braze-on adapter clamp, to make it easy to swap between cranks without constantly marking up the frame where it attaches. I would set the clamp to allow me to swap between ders and cranks whenever I like.

This whole setup would allow easy swapping of cranks depending on the terrain for specific races. Of course you realize, a triple would handle the whole range pretty much by itself, but weight may be a factor, and ease of use when racing may also be a concern when faster shifting is required.