So, let me get this straight, you would rather have one unit of Argyraspiday (966 upkeep) than 2 units of Pezhetairoi (502 upkeep)?

I cannot really see this ever being the case (unless money is no issue). Both are similar units with similar animations and almost similar stats. What warrents the huge difference in price?

Note: I am not trying to flame/troll/etc, I just want to understand.