

It usually means that 300 people were involved in the project at different stages of its lifetime. It probably also includes the people involved in sourcing the material, tools, people, workspace, etc. That’s probably 20 people who likely never touched the final product. There likely was also some marketing and business people involved. They did probably put hands on the final product for a photo op.
In a functioning government, that is not a structure that we would want because then judges would not be a neutral 3rd party (at least as intended).
There may be merit in the idea of moving the Inspector Generals under the Judicial branch however the but even that would require rewriting the constitution.
In reality, congress is supposed to have this responsibility, but our current congress is broken for a number of reasons.