I think is more like this. secretly release a tail monsters on a village that cant handle it and then offer to defeat it. since I'm guessing they can control the Bichu than they can just stop it when it has left the village week and in ruin, after that they can easly take over.
What Im wondering the most is what does a person like Itachi gain for been in Akatsuki, since his goal seems to be fighting people that can test his own ability. The others can probably joined because they want revenge on theyre village and I'm guessing Hidan wants to convert people over to his religion since he seems to so passionate about it