We've had multiple games with three players left, where it became clear one player is significantly stronger than the two other players combined. At one point the two weaker players realized this, and wanted to do a merger.
We've allowed this in a house rule when the two players' combined net worth is less than that of any other players.
Assuming every player is operating in good faith, is it possible to achieve "merger" to the same effect within the official rules framework?
EDIT: My question is, under official rules, can Players A and B operate under a united banner as if they are one player? Assuming both players have made the necessary officially-sanctioned arrangements so same-coloured lands are only held by one player so houses can be built? Can Player A and B allow each other to be effectively rent-free under official rules? In this way if Player X (not part of the union) loses, the game effectively ends, or under whatever arrangements needed for Player B to surrender under official rules?