Ideas and suggestions.

Why not add functionality to the library for diplomats? For example, a ring that reduces the required level by 2, a medal by 3, a ribbon by 4, and a toga that removes the requirements altogether. This wouldn't create a significant imbalance in the game, but it wouldn't be completely useless either – for example, you could use the library to level up a weak diplomat wearing a toga to gain the necessary knowledge, and so on. The main advantage is that it would increase the logical consistency and harmony of the game: the Burial Urn and the Fist of Ogre are excellent in this regard, so why not bring the Diplomat's Toga to the same level?