I've had the idea for a while, sitting in the back of my mind for several years now, of rather than simply adjusting stats, some Forge techs unlock the ability to train Medium and Heavy variants of your units. So, researching "Linothorakes" unlocks Medium units, while researching "Bronze Cuirass" unlocks Heavy units. Ranged units like Slingers, Archers, Skirmish Cavalry, etc. would only have Light and Medium options to train after your research "Linothorakes", and then you can unlock Light, Medium, and Heavy variants for Hoplites and Hippikons after researching Linothorakes and then Bronze Cuirasses.    This would replace the current promotion system. 

"Strategy Game Icon Style" (the standard I've taught the LLM to maintain):   Iconized for in-game: Athletic Dances (replaces "Feminine Mystique") Cost 300 Food 300 Glory Effect Spartan Women +100% attack.  Spartan Women +25% health.  Spartan Women +5 carry capacity for all resources. Description Ancient Spartan dance was closely tied to education, athletic training, religion, and communal identity. Spartan boys and men practiced martial dances, especially the pyrrhichē, which imitated combat movements—dodging, striking, advancing, and retreating—and helped develop rhythm, agility, and coordination. Choral dancing was equally important at festivals such as the Gymnopaidiai and Hyakinthia, where age groups performed songs and dances that celebrated discipline, military virtue, civic continuity, and the gods. Spartan girls also received unusually extensive physical training by Greek standards, and dancing formed part of that culture of public athletic display. The female Spartan dance usually called the bibasis (Greek βίβασις) was an especially athletic form. Ancient descriptions portray dancers repeatedly leaping upward and striking or touching their buttocks with their heels while airborne, apparently counting the successful repetitions. It was therefore less like a restrained ceremonial dance and more like a combination of dance, jumping exercise, and competitive athletic display. Both young men and women could perform versions of it, but Spartan girls became particularly associated with the feat. One ancient anecdotal tradition even praises a girl for performing a thousand consecutive kicks or jumps, although such numbers should be treated as celebratory exaggeration rather than a precise athletic record. For Spartan women, the bibasis fits the broader educational ideal attributed to Sparta: girls were encouraged to cultivate strength, stamina, coordination, and bodily confidence, rather than being confined exclusively to domestic accomplishments. The dance would most plausibly have been performed in a short, practical tunic, allowing freedom of leg movement, probably barefoot, and without armor. It was athletic, rhythmic, and distinctly Spartan in the way it blurred the boundary between dance and physical training.    

It's debated to what extent they just used an exomis before more protection made a comeback, but yes, I didn't mention it because that would be indeed too confusing. I counted mobility (as in agility) as "adding" protection because dodging and parrying would count for it (since they are not appearing independently in the game, I think). But that's just headcannon, I avoid mentioning that and just tried to make the linothorax look more complex and better than the bronze cuirass (if I didn't achieve that is in part because I ran out of free AI images ). In any case, both types of armour appeared before the time frame of the game, and evolved in parallel, that's why I relied more on a "when they started to be adopted more often" criteria, thus the fact that linothorax is preferred at later stages is what throws me off quite a bit. Another take could be if you have medium and heavy infantry (assuming light have almost no armour), and each would have their own armour tech tree (for linothorax and bronze cuirass, respectively and independently). That would not only make more sense, but diversify units better, look more realistic (with certain constraints, like Skiritai, asuming they are medium infantry, always using linothorax and Spartiates always using bronze cuirass, when in reality it wouldn't have been so monolithic), and add to the gameplay (particularly if, in general although situational, earlier techs make heavy units preferable, and later techs make medium units preferable, for the Greeks at least, and it's nice that this would depend on each civ). I guess this can be a big change, although not as big as some mod I saw not long ago where techs were too split into too many different unit types (and anyway DE is into more techs, if I'm not wrong ).