Pirate Ship doesn't scale with player count to the same degree as Revenant. The only way it scales is that it's more likely to "hit" with more players; Revenant's effect stacks for each hit. Revenant is like if Pirate Ship got a coin token for every Treasure trashed instead of just one if it trashed any.

And? In a 2P game Revenant could easily yield just 1 Coffers. Not a particularly huge benefit which is why I do not worry about the multiplayer case

That's only if your opponent doesn't buy anything, and it would be very rare for them to do that just to avoid 1 measly debt. In 2P games, it will usually yield 2 Coffers. In a 3P game, it suddenly gives +3 Coffers, and has an attack along with it. For just $5. Revenant is balanced ONLY in 2 player games.

Your scenario assumes that every single player has an Ambassador

True that, I did indeed implicitly assume rational play.

Sorry, I should have specified. Your scenario assumes that every player has an Ambassador

**AND plays them EXACTLY the same number of times.** That's very unlikely, even if Ambassador is SO great that not buying them in every possible set is irrational, which is itself an irrational assumption. No card is good in absolutely every possible deck. Also, I guess Witch must also scale with players according to you. After all, if 2 players play one, it results in a net 1 Curse for everybody, and if 4 players play one, it results in a net 3 Curses for everybody. I'll give you Noble Brigand and Jester, but arguing that Ambassador scales with player count is just stupid.

The thing about Noble Brigand and Jester is that sure, their potential strength increases with player count, but the chances of gaining more cards decreases with each card gained; you might consistently gain one powerful card in a 4 player game, but you're pretty unlikely to gain 3 Golds with either of those. Your Revenant, on the other hand,

**is just as likely to gain +4 Coffers in a 4P game as it is to get +2 in a 2P game.**