The way I see it is this.
All countries are only just starting to get into the Iron Age. Some will get into it more than others.
The ones more entrenched in the Iron Age could possibly have a Political Stat or something as they would be more likely to have various Political Groups etc. But the nations that are behind wont have this stat. They can essentially be seen as barbaric or something or not organized enough to have this.
As far as a tech stat is concerned I don't really think its needed. Techs imo shouldn't be researchable the mod should control this and all nations will progress as he sees fit depending on geo graphical need etc. For example I'm trying to mold Ferman into a naval power although it's probably not working
I would expect to one day possibly have better ships than the standard while other nations might move more into agriculture, Metal Forging etc.
The only stat I can think of that might be worth bringing in is a discription of the army and makeup. For example for Ferman instead of having like 1000 Spearman, 500 Archers it would be something like this.
2000 Men (Majority equipped with wooden spears with minimal armour, Small supporting contingents of archers and skirmishers, No mounted ability, Limited supply ability mainly relying on pillaging, no official training as men are called up in times of need).
So the stat would be. Number of men(Description of Melee troops, Description of Ranged troops, Description of Mounted troops, Destription of Supply ability, Description of Training)
I think this would be good to have since then each nation can mold their army and navy into what they think is best and since in ancient times armies were generally levied not professional the training stat can essentially determine whether the nation has a professional or levied army.
Anyway I don't think we even really need to have a military stat just slowly develop some countries ahead of others with extra stats and keep the rest with limited stats.
I haven't really read this post through and I typed it at work quite quickly so if it doesn't make sense I claim insanity.