Human players will provide the best challenge because the AI opponents in this game do not have different personalities... so you'll eventually master their behaviors. Hopefully in Dominions_3 the AI opponents will have random personalities assigned to them before the start of each game.
My suggestions if you can only do singleplayer:
1) Independent setting of 6
2) Large or X-Large Map(takes longer but worth it)
3) Set everyone with 3 starting provinces
4) Set all AI opponents for Impossible except maybe Ermor
5) Set the following as AI opponents:
a) ERMOR {the greatest threat in 95% of games}
b) R'yleh {pray he doesn't get a vastness}
c) Ulm {his dark knights are cruel}
d) Caelum {usually does air attacks far away}
e) Abysia {his summer lions don't play nice}
f} Jotun {They're giants... nothing else to say}
Last don't be making the game easier by giving them donations during the game. Take it as it comes.
And if you are really really brave follow the steps for making all these computer opponents allies which is found in a different topic:
http://www.shrapnelgames.com/cgi-bin...;f=74;t=001470