Even if the rule designer had anticipated both aspects and listed them, the boundary between "cooperation" and "manipulation" or "deception" is very thin and can completely intertwine.
For example, the initial alliance proposal by the Zento Family representative was actually "manipulation" and "deception" disguised as "cooperation," as the Zento Family representative wanted to create three shields to take hits for him. Only after considering the further future did he redesign the strategy to turn the four-person alliance into pure cooperation.
This shift can happen very quickly and is difficult to distinguish. The more the game designer tries to create restrictive rules, the harder it will be to restrict.
Unless the interaction between players is completely isolated from the start, turning this game into a purely bidding game.
But by then, the noble families would likely not accept it.
