The AI didn't build up correctly. That's why it always only built up peasants and nothing else... This patch is thought for modders,who want to make the campaign a challenge, but always despair at the stockade-bug. I made a fast mod for the Viking Campaign for my own. It isn't balanced very well, but rather challenging. If I have time enough it's possible, that I will release it sometime, but now I'm working on so much mods I don't want to promise anything...
To see what the patch has repaired, start a game in IAN-mode (google for this, if you don't know what I'm talking about), turn on god-mode and watch the castles. They get always stuck if they are warrior holds... Then patch the game and repeat the pocedure. Now you will see, that the castles are built up correctly...