I wouldn't say the 1st green is benign at all. Maybe the back 1/3 of it. The different rolls in that green from the front to about 2/3 back are brilliant and difficult. That is the genius of the design on number one. Very few players have the game or the stones to attack a back hole location and playing conservative to the front or even the middle leaves you with a very tough two putt to start your day.
As for those who have mentioned #5 and might have an opportunity to play PV this year, you will notice that #5 green got a similar renovation to #2 this off season. It appears that the overall slope from back to front has been softened, as well as the very back portion of the green. The front part was changed slightly as well but the false front that was there is still part of the design. Prior to this change, there was only about a 5 foot area in the back right for a rear hole location. Now it looks like there is cuppable area from the middle back over to the right. Also, a golfer who hits a tee shot on the green but in the back part of the green will at least be able to keep a putt to a front pin on the green. With speeds of 10.5-11+, it was nearly impossible to keep a putt on the green before. It takes a damn good shot to hit that green anyway, I've always thought there was too severe a penalty if you happened to have your ball stay on the green in the back when the hole location was front. Even with Crump's desire to create a stern championship test, I doubt he would have ever envisioned or wanted his greens to be unputtable in certain spots.
I was thinking about the renovation of some of these classic greens and I think the discussion deserves it's own topic.(I'll post this last paragraph into a new topic) Obviously we all love many of the green designs at courses like Pine Valley, Merion, etc but when really analyzing these greens, we have to understand the green speeds at the time they were built and what the designers might have thought green speeds would become. I would say for almost certain that the architects at the time could never have envisioned greens running at 11-12+ on a Stimp. In that era, greens were near 4-6, with 6 being what they thought very fast. We now have fairways that are quicker than that. I just think it's important to think about that when people are quick to criticize clubs for softening current greens a bit. I'm certainly not advocating flat greens, but I don't think the challenge is diminished much when you combine today's green speeds with some softening in certain areas. If you take all the greens at PV for example and compared the challenge in putting at current speeds to that of 30 years ago, it's not even close. The greens would be incredibly easier with a stimp of 7-9 feet. I don't see technology going backward in regard to agronomy or equipment, it never has. So clubs have to deal with the present situation and determine what they feel is the correct way to present their course as a relevant challenge.