[Cainehill]

Other possibilities:

Another line of research, along the lines of Construction only affecting the recruited troops. "Armament" perhaps? It could work in any number of ways, including:

Allowing new buildings : Example, at Armament 2 Ulm could build a "Mithril Forge" that gave +1 attack + damage plus affects ethereal units. Some buildings might be cheap, some expensive, perhaps on a nation by nation basis.

Allowing the choice of a new ability for nationals : Armament 2, Ulm gets to choose between Enhanced Black Steel Weaponry or EBS Armor. Weaponry gives an effect as per above, Armor gives a 25% resistance to elements.

Give a new category of spells, "National" like Global, only each nation can only have say, 2 national spells up, each giving a certain effect to the recruited troops.

Sadly, these certainly can't be fit into Dom3. It's a shame really - most suggestions are either bandaids, or wouldn't fit Dom2/3 (though perhaps IllWinter has been doing things none of us has thought of to remedy the situation).

One thing that allowed games like MoM to have national troops that remained viable against high powered summonings was the unit enchantments - but you'd need a stack / unit mechanism that Dominions, with individual troops, doesn't have, whereas certain MoM enchantments were quite effective with differing troops. Halflings sucked - but having the most individual troops possible in the unit meant a few enchantments got extra oomph on them. Berserkers similarly were candidates for enchantments, being tough and having a thrown weapon in addition to melee, so they could attack flyers.

Ah well - have to wait and see.