Since Heroes are soldiers with a formidable and commendable performance in battle. I thought some ideas in order to let greeks the cance to increment the number of heroes that could even be combined:
All 4 Major god heores (or maybe increment it to 5) avaiable since Archaic Age but they are weak, and they upgrade their strenght every age up.
Some method of promoting units to heroes depending on their performance in combat.
Here I thought in 2 methods:
Every unit that kills some determined numer of units of deals some amount of damage, can promote to Hero (wiht some animation wiht delay in order to promote out of combat.
Every determined numer of kills with a type of unit gives you a promote to hero. For example, every 5 kills with Hoplites gives you 1 hoplita promote to hero.
If anything this is a good basis for a hero mechanics for a new pantheon (I think it’s similar to alpha norse).
Greeks are unique as is. Few strong vost efficient heroes. Where others usually have rather expansive and inefficient one with the redeeming quality of countering myth.
They sre still cost efficient compared to other civ’s heroes.
Compare a hersir or hero murmilo and the first hero. For a comparable cost (and even lower in case of murmilo), You get more hp more bonus vs myth, and no infanty or any other label, hence no taking bonus damage. (Also shoting at flyers).
Where other civs heroes are more expansive but not stronger than normal units (hence the myth, human, hero triangle) greek heroes are stronger than human units, so their downside is their numbers being hard limited.