Holy God this thread is full of misinformation.
To the OP, I have no idea what "basic greek unit" you're talking about, but the most basic ones are the "Youth" units, ex. "Peloponnesian Youth" which are equipped with spears and tunics. No shields, no armor. Those are the very bottom tiered units.
Yet they never appear in any armies. All Delian armies I have encountered are around 90% hoplites. Also, if I go to a city, it gives hoplites not youths.
Also, the Persian army was made up primarily of "disposable" soldiers equipped with wicker shields and little to no armor.
BS. The "Persian" army was made up of a large variety of different troop types. The Ethnic Persians fought as a combined force of spearmen and archers, the spearmen being trained and equipped with large wicker shields (a heavy wicker shield is equal to a wooden one, really), spears and armor. The archers were unarmored, but they weren't meant to fight. Then there were the heavy cavalry. As far as auxiliaries go there were different types, like Egyptian hoplites, Assyrian heavy infantry, Saka cavalry and countless others. There were no untrained disposable soldiers there, really. Light troops =/= disposable, untrained weaklings.
There's no way they could have assembled an army of several hundred thousand professional soldiers, though there certainly were very elite units. Persians were also never trained in Hoplite tactics, and so would almost certainly experience heavy losses when charging head-first into a Phalanx, hence why around 6,000 Greeks managed to destroy 20,000 Persians in the 3 days of actual battle at Thermopylae. Tactics. Plain and simple.
Again, bullshit. At Thermopylae there was no way they could physically lose 20 thousand men. 20 thousand men was the total number of men sent at them!
Day 1 - Mede sparabara sent to attack the pass. No progress made. Recalled.
Day 2 - Persians sent against the hoplites. No progress made. Recalled. Another pass discovered.
Day 3 - Persians sent against the force guarding the second pass. Breaks through, cuts off the rear. Attack against the front and rear of the hoplites. Victory.
The point is, the game is rather unbalanced. There is no way you can field more hoplites than light troops.