The AI does not seem to respond to diplomacy. But it doesnt mean you cant use it.
Lets say that you have scouted out that you are coming up on nation-A using lots of undead in their armies. And on the far side of nation-A is nation-B who is not doing so well. Having nation-B lose too soon would make nation-A very strong. So you forge things like Herald Lances to send nation-B. It allows nation-B to hold out much longer. Plus, when you finally reach nation-B the fact that they have herald lances is not likely to cause you much trouble.
Sometimes it can even be useful to send gold and gems to an AI that you are not fighting but is on the far side of who you are fighting. Not enough to make them powerful. Just enough to keep them holding out and force your enemy to move armies that direction away from your front.
Remember, the enemy of my enemy is my friend.
Gandalf Parker
--
per peer-pressure preoccupation
My maps, mods, and mullings can be found at
http://www.Dom3Minions.com