Yes the Dom3Minions server is for hosting Dom3 games with full availability of all the Dom3 options you have ever seen or can dream up.
Allied AIs are usually done map commands added to the .map file. You might want to generate one or make a copy of one so you dont mess up a map you mght use later in another game.
The nation numbers can be found here.
http://www.dom3minions.com/docs/nations.txt
the map commands have a document file in your dominions doc directory. Or a quick reference version here..
http://www.dom3minions.com/docs/map_qref.txt
so in an early era game, adding these commands to the .map file
#allies 0 1
#allies 1 2
#allies 2 0
Would ally Arcos, Ulm, and Ermor so that they will not attack each other.
OR depending on how big a game, you can grab one of the always-open games on my server
http://www.dom3minions.com/HostedGames.htm
I have scripts that add randomly chosen AIs on some of them
OR you could just send me whatever settings you had for the LLamaserver game plus whatever you wanted to add, and I can setup a game for you and your friends.
There is also some writeups available on running a game on my server or any other which have some feature options listed.
http://www.dom3minions.com/HostingGames.htm
There are also more options for boosting the AIs in Dom3 games. The vanilla AI is completely random which can offer surprisingly good moves but more often surprisingly dumb ones. However there are game settings, map commands, specific maps, mods, and modded nations all of which are designed to increase the AIs performance. In fact I have yet to feel that a dom3 game using all of them at once is even playable