You are joking right that Xerxes' was the only major naval invasion of the classical period...I can name a bunch off of the top of my head:Caesars invasion of Britain, Roman invasions of North Africa leading up to the Battle of Zama, the entire first punic war, the siege of Syracuse by Athens during the Peloponnesian war, the aforementioned invasion by Pyrrhos, attempted naval invasions by Macedon during the first Macedonian war just to name ones off of the top of my head. Im just not a fan of not having them on because casse never gets touched unless by the human player, and Koinon Hellenon gets stuck on rhodes etc etc...Its just enough to keep some me honest a bit playing as some factions (example carthage with corsica and sardinia).