The official number is 100. Each one killed will respawn up to 24h later. They can be given any order within their limits, and can go off in any number of groups I choose. Much like any colony stand, their power comes from being a group rather than single. I can also summon any number I want, so it doesn't have to be all 100. It could be 5 at first, then another 2, then the other 93. . 