They had to consider the possibility that Cyrus was lying to them, that he was intentionally pushing them out to be two sacrificial pawns. Thus, while they were filling their treasuries, Cyrus was secretly withdrawing money to prepare for a robbery phase in the later stage of the game. As for the mutual exchange of money in the treasuries, it looked fair, but what if this was also just Cyrus's trap? After all, Cyrus's side was the one withdrawing money, and knowing for sure he would not be robbed until near the end of the game, this was no different from an agreement that existed only in name.
Under that situation, the Zento alliance was no different from a safe harbor; those four players would proceed with a financial exchange.
