Wassup, since there's not an specific model of what a war event should be, I'd like to give my idea of a war event
"There are many causes behind the wars in the world today. The control of natural resources, inequality, conflicts for ethnic, commercial and technological reasons, the rise of extremism and nationalism, or the adverse effects of climate change."
The war events can be made in an alter version of one of the 3 current villages (Let's suppose a destroyed version of Leaf Village), the map is big enough like to can give 1 starting point to each village on each corner of the map, the goal will be like a Domination event, the villages will create their own strategy about how to take those points, a village gets disqualified after losing their main point (The spawn one), people who get BI cannot leave the hospital until the timer goes off, this will force the commanders to play knowing the risk of each movement, also it'll leave chances to the others to get advantage once their rivals makes a mistake, the winner would be decided by taking the main spawn point of the other villages, the taken points would give some kind of buff to the village depending on how many they got, this can go from free supplies, spawning points, less bi timers to stat buffs, the event winner would have a chance to get benefits from the other two villages, the losers villages would be under some debuff as well, dats ma idea