I have never bought any rootlets to plant, but I have transplanted several and mine have always done well, near 100% come up the next spring.
But I would dig mine one day, and place the root in a bag of damp leaves and dirt until I got back to my home spot, and then plant them the same day. Being especially careful with the bud spur.
The bud spur is quit sensitive, and after it has developed - if it dries out or gets damaged, you get no top the next year. But as long as the root has enough stamina / substance, over that next year, it will develop another bud spur and send up a top the next year.
My best guess on your pound of rootlets that almost none came up, would be some kind of bud spur damage.
On your one that came up and wilted and died... could have been any number of things that attack ginseng on a regular basis, fungus, root rot, etc (some kind of disease)... or even moles / voles - if they find a seng root, they will eat it or a good chunk of it. One could have eaten the top half of the root causing the top to immediately wilt and die.
If the bottom half of the root is still in the ground, and still has enough stamina / substance to it... in a year or two it may eventually develop a bud spur and send up a top.
Ginseng can reproduce vegetatively... for example if you had a good sized long root, with a bud spur on the top end, and you cut that root in two pieces (in the middle)... the part of the root with the bud spur would send up a top, most likely that next spring. The part of the root that had no spur, would remain dormant for a while, a year or two possibly, but would eventually (most likely) develop a bud spur and send up a top. So from one root, you eventually get two separate plants.
The success rate on that is not anywhere near 100% but it does work. A few years ago I did some research on that - there is quite a bit of info on the internet if you look around for it.
Nice Looking 3 leafers...
A caution on 3 leafers, you can plant seed in a location, and have great germination, and some really nice 3 leafers, but if the location is not right, those 3 leafers will remain small weak plants, and 4-5 years later, you will have a few scraggly 2 prongs and some big 3 leafers in that spot. They just never really develop, and what does survive stays small and weak. I planted several places in my early days, where there was no wild ginseng growing, thinking well it might just work here. And I have several places that I put in test plots like that, that are exactly as I described (4-5) years later.
You really need to see a test plot thru to year 3 to determine the success of it. If at year 3, you are getting quite a few 3 prongers, and some are starting to produce berries... I would say that is an excellent sign of success for that area.
Just because you have a nice wad of 3 leafers the first year, don't get too excited about it... it takes time to prove success when it comes to seng growing.
Good Luck !