If the pirates are totally greedy but totally honest the 3 oldest get thrown overboard one by one and the oldest of the 2 pirates that are left gets to decide and could decide to keep all the coins. But...

But besides being greedy they probably are not honest. As soon as the oldest gets thrown overboard, there would be a battle royale throwing everyone possible overboard and the survivor would keep all the gold coins.

To understand pirate mentality, just watch a few episodes of the WWE.

However the oldest pirate didn't get to be an old pirate by being stupid so he would make a plan that the 3 oldest pirates each get 33 coins and don't get thrown overboard. That leaves one coin left for the 2 youngest pirates to keep them busy fighting over it.

But the oldest pirate is smart enough to know that if either of the 2nd or 3rd oldest figures out that with the oldest overboard, then they could vote themselves 50 coins each with their 2 votes. So the oldest decided to give the 2 youngest 5 coins each, and keep 90 coins for himself. The 2 youngest know that if the oldest gets thrown overboard, then they might get nothing so they agree to the oldest pirate's plan. The 2nd and 3rd oldest get nothing.

Then the oldest pirate went into politics and is still cheating everyone he can, buying votes and keeping the riches for himself.

😵