I don't think it saves Rolf's point:

The actual US armed forces are a few million. 5% would be a much better estimate. This aside, you are ignoring that "lethal autonomy" is nowhere near the same thing as "operational autonomy". A Predator drone requires more people to run it - fuelling, arming, polishing the paint - than a fighter aircraft does.

If you are getting >6x more flight-hours out of a drone for <2x as many people used as compared to its alternative, then by switching a fleet of alternatives entirely to drones, the effectiveness or lethality increases by >6x for an increased man power of <2x - even if you keep the manpower constant and shrink the size of the fleet to compensate for that <2x manpower penalty, you've still got a new fleet which is somewhere around 6x more lethal. Or you could take the tradeoff even further and have an equally lethal fleet with a small fraction of the total manpower, because each drone goes so much further than its equivalent. So a drone fleet off similar lethality does have more operational autonomy!

That's why per flight hour costs matter - because ultimately, the entire point of having these airplanes is to fly them.