Phil,
All other things being equal, I do try to vary the distances and "effective distances" considering wind and elevation changes, of the typical approach shot, but fitting the land is probably more important. Golfers occaisionally comment on too many approaches of the same length in a row, etc. so I think they still notice a balance of shots.
That said, golfers also use one swing anymore, rather than the old days when each club type seemed to require a different type of swing (pre balanced, matching shafts) so its not as important as it was, IMHO. Better golfers seem to recall different types of shots being required, which becomes a more important design criteria for me.
You could hit three 6 irons in a row requiring high, low, wind directions, lie slope, , high or low spin, fade, draw, etc., and each would be a quite different shot.