Change Conquest Victory to only require ownership of a portion of all Settled Systems, not all Systems in the galaxy.


Genghis Khan had the largest contiguous empire in human history, and the British empire was the largest over all. That wasn't because they managed to take over and develop most of all the Earth's surface area, but rather it was because they ruled over the most people across the largest area. 


To be a great and terrible conqueror, you don't need to own most of the land that exists; you just need to own most of the land that people actually live on. If you are the undisputed ruler of all settlements that actually exist, you effectively rule the world, because you rule the only part of the world that matters to the people living on it. The current Conquest victory is silly as a result, because no matter how much bigger your empire is than everyone else's, it only matters if you've expanded to cover most of a galaxy that is about half composed of planets and systems nobody else really wants. 


Also, this would more neatly tie into the math of the current Overcolonization limit upgrades, since they wouldn't need to scale the Overcolonization limit to fit the galaxy, as now the Conquer Victory is based on the Overcolonization limit and your opponents willingness to ignore it. It's a game of chicken to see who is willing to expand furthest.