This was actually one of my frustrations in the JAG project.
We actually had an establishment increase of three paralegals as information/knowledge managers. They were in a very low pay classification and thus were regularly hired away by Justice.
The biggest issue, however, was getting buy-in that there had to be a supervisory structure over them which would require some supervision from the O-4 and O-5 level. My predecessor had envisioned some type of Wikipedia like system. Any one who knows law knows that you can't go to Wikipedia for black letter law.
Expecting O-5s to have the time to manage an information/knowledge base, even with para-legals, however, was seen (and probably was) unsustainable.
That's generally the problem with knowledge management. Unless you are looking at something loose and search engine based it will need a level of continuous effort to keep it authoritative. Most organizations can barely keep up with records management much less knowledge management.