I have to disagree with what you said. While being part of the community in the last 15 years there were always two major complains about the first installment. First, the game is way to easy, make it harder. And second, the court is way to small make it bigger.
I always thought it is strange because one thing tried to fix the other. Also, gameplay-wise it is way more fun to control a small group of armys on the battlefield. Where would the limit end? If we would be able to create, say 20 armys, it would be one big mess. The game wouldn't be fun anymore but just tedious to manage.
Also, many of the improvements in the 3rd dev-diary did act upon the implications you mentioned. All member of the royal court can now have armys, so you can at all times have up to 9 armys on the map (which in my opinion is too much, especially for smaller realms). Only if the member is a marshall, his army can be bigger. So you can have your diplomats and spies and merchants with small armys defend the realm from lower threats (e.g. rebels) while the marshalls gos into battle with the best army.
So, i think we will see games having 1 king, 2-4 marshalls (big army) and 3-5 others. Since they can have armies aswell, the can protect the realm behind the big city walls while the marshall will meet the enemies on the field. That should do great for the diversity of games.
For my part, I just hope that there is no spy-action that instantly lets your whole court revolt. But as far as I can read between the lines, they fixed that aswell by implementing a loyality-system so that only some of your men will turn into rebels, but we'll have to see.
Greetings!