“Remember Salamis” is an interesting tagline.
If the Athenians were not willing to leave their city for Aegina, and not willing to accept a Spartan “Admiral”, the Persians very likely would have won the Persian War.
So you see, we are not in a unique situation here.
2. The Athenian fleet was conducting an evacuation of Athens, when the Athenian Commander, Themistocles, interpreted the Oracle as saying that they should build a wooden wall to save them. Themistocles believed the wooden wall as a line of ships, so he decided to defend Athens on the sea.
3. Interestingly, you mentioned the Spartans. The Spartans wanted to go back to Peloponnese and defend Greece on the ground, which would have failed. If they had listened to the Spartan Generals, Greece would have been snuffed out in its infancy.