What I mean is, would they even have to actively try to start a war in order to get one? Think about it. Suppose you are the Lord of Red Vegetable Country. You have a tiny group of ninja who really can't do much other than collect intelligence. Meanwhile, your neighbor- the Lord of Blue Moon Country- has slowly been creeping on to your land, and is looking at your territory with covetous eyes. You can't really respond, because he not only is larger, but he has the wealth to hire good Shinobi to screw you over. Then suddenly, a Man in Black with Clouds shows up. Your ninjas identify him as an S-Class criminal, but he tells you that for a low, low price, he'll perform a mission for you. If you were a Daimyo being essentially squished by a neighbor, wouldn't you be tempted to hire the low services of this man to teach the bastard a lesson he'll never forget? Essentially, I think that Akatsuki could get wars started simply by making themselves available amongst the minor lords to settle grudges in a brutal way.