Ken,
Even without fw angles, I agree you can have a green too small for strategy. Again, using the USGA handicap and slope guide, it seems most player (about 2 of 3 based on empirical evidence collected for that book) will hit a target about 15% of its width of the approach shot (i.e., 15 yards wide for a 100 yard approach shot, 30 yards wide for a 200 yard approach shot.)
If the strategy is to be aim at the middle or aim at the pin, it would seem that a green would have to be wider than the "recommemded" approach length width - aiming at the middle requires the 15% and then tucking a target requires somewhat more. Depending on shot pattern, wind, etc., without that width, aiming at the middle may be just as risky as aiming at the tucked pin.
Which brings up the other possible reason for "oversized" greens - just whose approach shot do you design for? The 300 yard hitter on a 450 yard hole? Or the 190 - 230 -260 hitter on the middle tees of that hole who might have much more approach length? Bigger greens are more conservative for play reasons, too, not just maintenance reasons.