Ordinarily, Ghost Ship is a pain to deal with. Do you wreck your current hand, or do you sandbag your next one and hope to get something out of this one?
Tactician changes things. Put your good cards back on the deck (to be drawn later), then discard the bad cards with your Tactician. Tactician helps against every attack that cuts hand size, but because Ghost Ship places cards back on the deck instead of discarding them, it’s the only attack that ends up helping Tacticians rather than hurting them.
Sample Game: hausdorff’s turn 5 Ghost Ship lets rrenaud save his Bridge from turn 6 for turn 7. The Ghost Ship enables rrenaud to play two bridges on turn seven. Without the opponent’s Ghost Ship, rrenaud’s turn 6 would have been no better, and his seventh turn would have been significantly worse.