David:
It is impossible IMO to project what greens might work best from the photos you show, simply because they are only a snap shot and don't show the entire hole with all the physical conditions that led to the greens, not a criticism of the pictures. When I first started, I initially approached the design of a green site while thinking of length, difficulty, etc. But that didn't last very long as I could quickly see there were too many other essential factors, natural features, man-made, topo, wind, firmness of soil, short-vs-long grass around putting surfaces, shot angles, etc, that had more significant influence on the 'actual' design of the green.
I do think there is a correlation between length and green design, but there is so much in between those two elements/parameters that must be taken into careful consideration to get it right. The correlation, however, IMO is overblown. On the other hand, many architects do design this way, with a tighter/stricter relationship and do just fine with it, but I don't believe you end up with the best design given the site conditions that led up to the green site and around the site itself. Usually, it is a bit more manufactured looking.
There are a couple of par 5's I built some years ago that sport fairly large putting surfaces and almost every player must approach them with a wedge due to their long length. To this day, both rank among the toughest holes on each course because of the subtle, but interesting contour built in the surfaces and the relationship to the surrounding terrain. The surrounds say one thing but the greens don't agree.