There are two kinds of people: deontologists and utilitarians. Deontologists care about so-called “rights”. While utilitarians care about maximizing a particular metric. Possible metrics include minimize suffering, maximizing human happiness, minimizing human death, etc. Anarchy is probably the best at all three, but particularly at minimizing human death.
To start with, you might think about how to solve the problem in reverse. How would you kill the most people? You could kill one or two people if you plan it out. The dead end with this approach is that a family member of one of your victims is likely to retaliate and kill you. Another approach would be to show up at a crowded gathering and go berserk. Those will be a few tragic deaths. A far better strategy (at least in this scenario) would be to hire other people to do it. You could get several people to go berserk. It’s not a long term strategy though. Long term, you might want to target health care professionals. Every day, those jerks go around healing thousands of people per day, saving countless lives. If you really want a long term solution, don’t kill them. Limit the number of people allowed to be doctors. Prevent the worst performers from helping people. The few who are alive will thank you for it. It’s possible that those worst performers would accidentally kill a few patients, but on the whole, they probably would have saved more. Prevent people from taking experimental drugs. Even people who are on their death bed, waiting for a miracle in the form of a tiny dosage, should die painful deaths because you didn’t give them permission to take a drug. Call it the FDA. People will thank you for it. Prevent the sale of human organs. Humans who need organs to live don’t deserve to live. They should die with their money. No one should live without your permission, from a utilitarian perspective.