Turtle Ships, Elephant Archers and Tarkans, are supply effiecient.
We already saw multiple buffs to Turtle Ships, Elephant Archers and Tarkans, and look how frequently they are used now. Hint: Just as much as before the buffs.
But you still will not be convinced that a 20% price reduction for UNUSED UNITS WE, Turtles, Condos, TKs etc is still balanced.
UUs should be balanced for that particular civ first and foremost. So that ech UU becomes a VIABLE option for that civ, and is seen.
Generic Units available to a civ should never take all the viability space of a civ’s UU.