Remember that every action you take makes you lose a stone, except for Negotiate. So you only have a limited number of moves to manipulate the board, while also wanting to have the most stones of the winning color.

Try to manipulate the board with the "wrong" color stones, to put the one you want to win in advantage. Like moving a certain color into a bad spot to make another color's spot better. Just keep in mind every stone you spend on battle and march makes that color's tie breakers stronger. Recruit won't mess with tiebreakers.

Another strategy is to mooch off of other people manipulating the board for you, while you keep more stones in hand than them, possibly using negotiate to tune your hand to the right color. Just remember every time you negotiate, you risk ending the game if your opponents decide to do it too.