I think that the commitee approach is a part of the problem. People from all over Europe meet to divide up the available codes.
When you take into account civil domestic, transit, super domestic, sector codes, orcam etc its very easy to see where they all go.
Our radar can often see foreign military codes over France and Holland causing numerous problems. In the octal system with 4 digits you get 4096 codes. 7000 / 77/76/7500 are obviously reserved but so are many others...... each ATSU has its own block of codes allocated to it. Often these units are closed at evenings and weekends. Why not use these codes when they are as a short term measure? Complicated but could be done.