I'm going to sound like I m bemoaning things here which I'm not because it is what it is and will move as it does.
Giving a numerical advantage at start up makes it more likely that a realm will recruit more based on the likelihood of playing with individuals you may know already and like. So a tilt from the start will have an early influence... ongoing that will change hopefully. Money and land advantages are far less than the advantage of a greater number of nobles.
You of all people should be used to challenging situations
