The AI is terrible. Not a challenge at all. I have not played all the scenarios, but the only one I have lost so far was on one of the conquest islands that was really small. Took me 6 times to figure out how to beat the AI. All other scenarios are not even a challenge on level 5 AI.
Problems with AI I see:
1 - risks its pieces to grab a pointless hex. Then it can be cut off and destroyed.
2 - favors attacking another AI over the player - I have left stuff unguarded and not gotten it taken
3 - never builds economic centers (or very rarely).
4 - does not build level 2 forts early in the game (btw, this is the key to winning)
ronin-mg-52 about Conquest! Medieval Realms