This utterance may get me horsewhipped, but I do not find the par-3's at PV all that difficult. I base my feelings on the size of the greens. For a good iron player, you really have to whiff one to miss the putting surface.
PV, in my view, is not about difficulty, but psychological terror. The fairways are wide and the putting surfaces expansive. Oakmont - and Shinnecock - place a higher premium on perfect shotmaking.
#3 is an enormous Redan. All you need do is block-nudge a five-iron somewhere towards the right side of the green and you'll be dancing. Now, the enormity of the putting surface introduces a 3-jack, but I think we are trying to identify par-3's where a train wreck is almost an inevitability.
#5 only requires a 200 yard shot with a draw. Death to those who fan it to the right side, but there is no real requirement for precision, just a good swing that cheats the ball left.
#10 is a simple hole. Pull out your 8-iron, aim it at the DA and don't try to get cute. Hit it. The green is 3X as large as it looks from the tee.
#14 is the same shot as #3. Downhill to a target that is far larger than it seems. The hole plays shorter than the yardage, so all that is necessary is a decent swing to an expansive landing area.
The problems start when the fairways begin to narrow in your mind. The monster is not real - just an illusion. Disasters are wholly self-inflicted at PV for the better player, because the golf course is not that hard. The margin for error is enormous - only a complete shank spells eternal punishment; negative thoughts begin to sneak into your head.
At Oakmont, with the exception of #8, a little, itty bitty miss results in a game of ping-pong between the bunkers and a putting surface faster than glass with more pitch.