A very primal tech that allows the construction of all wood based units
ex. Catapults, ballistae, (up and coming ones like mantlets, pallisades, siege towers etc.)
Cost 1 turn (im feelin generous)
What about this?: Adcanced woodworking
Reduce the production time of non-flesh-and-blood units by 1
OR
Incrase armor and health for non flesh and blood units
Lower cost 1 turn makes units unbalanced. Like ballista cost 4 and lowering cost by 1 turn is 25% from original price and same with catapult that cost 8 is 12,5%. Maybe advanced woodworking should lower workers wooden unit building time with 10%.
The better is decreasing of their turn because in that way this tech will be use full a they said the advancement acquired in everything now the weapons are high-tech and more advance like in the middle age when they create a things in same way they will know to create them quickly than their doing it slow because they create lots of their so they know how to create this quickly as a techniques
Instead of decreasing time to be built why not increase the health and armor for all wood units. Increase Hp by 8 and increase armor by 1 and pierce armor 1.