The Hungarian plan to send the Blucher class dreadnought SMS Mjolnir to join her sister ship SMS Szent Istvan in the far east theatre created a major diplomatic upset. Ironically it was the Prussians (who had sold both ships to Hungary) who were concerned two dreadnoughts would upset the balance of power in the region. Hungary insisted Mjolnir was the only fleet asset they could spare, and claimed the two dreadnoughts were no more powerful than the fleets already present.
Eventually a compromise was reached. The nations involved agreed the total reactor output of all "Large" or "Massive" warships (defined as having displacements above 12,000 and 20,000 tons respectively) deployed between longitudes 97E and 177W (between India and Midway) was not to exceed 500 MW. This level allowed Hungary to deploy two dreadnoughts, but not with sufficient reactor power to run their shield generators.
This is an in-universe explanation for an informal rule our circle has agreed to - no more than 50% of points may be spent on Large/Massive ships. Which is enough that I can fit my two dreadnoughts in 1000pt games, but only one of them can have a single shield generator.