Well, with a 100% trained requirement to get the knot, I don't see to many of those being earned. That is, of course, unless we have a rash of pencil-whipping the records.
In all seriousness, it often is difficult to get 100% trained in all positions. Adult leaders have families and other obligations and are sometimes single parents. It is difficult to add 3 to 6 more hours a month to the "one hour a week" for training. Training is usually at the convenience of the training teams schedule and why not, they have families and other obligations, too.
I would not be in favor of the Pack Trainer doing Leader Specific unless they have served in that position but I would favor all the others. Unfortunately, I can see the scenario FScouter described playing out all to often.
There has got to be some sort of balance that can be found. Improve the convenience to adult leaders while at the same time ensuring quality. Of course, there is probably a Nobel Prize waiting for the one who solves that!