I believe you meant par 5 for #4, not par 3.
It's also not the first time that Strantz has used the "scar" bunker. He first used it in front of the par 3 17th at Caledonia.
If I had to complain about TR and Caledonia, it's that the par 3's are all close to the same short length. There are no long par 3's and only a couple mid-length par 3's. Granted the difficulty is usually higher with the shorter par 3's, but I still think there needs to be more variety.
There are 5 par 3's at both TR and Caledonia. Here's the run-down on the back tee length of the par 3's at each course:
TR: 165, 148, 184, 152, 142.
Cal: 187, 157, 118, 167, 156.
A couple of notes: The first and third par 3's at TR were actually lengthened from the originals that used to be 152 and 178 yards long. The fourth at TR, #14, has essentially been shortened considerably. It originally had a back tee at 194 and the next tee was 178, but each were too hard for the extremely narrow target green surrounded by water on one side and difficult waste area on the other.
As Ran has conjectured and I wholeheartedly agree with, I think that at TR, a long uphill par 3 between #12 green and #13 tee should be added to replace #17, which has a ridiculous "diode" green with pin placement either way left or way right only separated by a 3 yard wide (a guess) strip of green. It's also just a pitch gap wedge from the tips downhill where you must double back from the green to get to 18 tees, which are next to 16 green and 17 tees.