We need to hit a middle path, not go back to the large realm extremes of a few years ago which were just as much an issue as not enough nobles in a realm. You need enough nobles in a realm to sustain activity, but not a realm so spread out over so many regions that it takes forever to march to war. This requires accepting less realms and less regions overall and pushing realms closer to one another. That requires player participation. Mergers, nomads, and such are tools to help players do that.