Actually, if you include all wars that have occurred from government in history, I'd say the number of deaths compared to corporations is a much higher multiple than that.
I think it's an interesting question to consider how much of that is due to corporations being legally constrained from the sorts of violence governments engage in, particularly in a thread discussing relaxing legal constraints on corporations.
If corporations were sovereign, I wouldn't be surprised at all if they participated in comparable levels of violence.
The East India Company would be a good supporting example or, more recently, United Fruit Company giving the world the term “banana republic”.
I think the corporation versus government phrasing is obscuring the underlying problem of power without accountability to the people. That’s going to end poorly no matter the exact relationship between the private and public sectors.