I know this is a really old thread at this point, but I feel like your "expertise" is spreading misinformation that needs to be corrected. Corsair may not be the Lost Spirit Ship, but it has its uses.
1) It's a third-tier flying unit which shoots air and ground independently, and the ground attack knocks small and medium units around with a decent splash radius.
2) It lets you summon Banditos on demand, 4 per ship, for 30 power each. Banditos who, I may add, get a 50% damage increase for every 3 friendly units nearby (including each other), up to 150%. That's roughly 1650 attack powe