Alright, if we want to be technical. Outside cultural biases many customs of the Greeks did not hold strategic or tactical value. While it made sense for a Greek leader to stand at the front lines in order to gain respect and honor for themselves such a standard can be harmful for the military success of an army. This does not mean they're stupid, but breaking down a military tradition with current knowledge will show they most if not all cultures did not run completely on practicality and total efficiency.