[Sombre]

I don't think that MP necessarily excludes new nation mods. It's true that you should probably only use Amos' nations (for example) against each other, not against vanilla sides, although you could give a stronger mod nation to a less experienced player and I doubt it would be so overpowering that he would roll over a seasoned veteran of MP. A lot of the new nations are built with balance in mind and have already undergone many changes to bring them in line with the vanilla game - furthermore, most of them aren't final versions, so unlike vanilla nations they are totally subject to further balance and gameplay improvements. What seems to be lacking a lot of the time is feedback from players to help balance the nations, especially for MP.

I see no reason why a MP game between members of an established group shouldn't make use of one or two mod nations, especially if the game is relatively short, on a small map etc. If there are some balance issues it probably isn't going to be enough to spoil the game - you can give feedback to the modder afterwards or even make some changes on the fly (provided everyone gets the latest version of the mod).

Of course I take the point about Dom3 not exactly needing new content - there are already a silly number of units and spells and whatnot, but then people seem very enthusiastic about more nations and the like being added in patches,.. so there must be desire to see new nations,..

I'm a big fan of Zepath and Amos' work too by the way. They inspired me to mod and their .dm files were a big help as I learned the ropes.