Interesting. I'm not sure if I understand correctly all what they mean, but would it mean, that a German stick grenade has the same 45% chances of incapacitation at 9 feet, as Mills bomb at 10 feet? Only one feet more?
How much radius is 1550 and 350 sq.ft?
In a meantime, I've found an article in Russian on F-1
http://army.armor.kiev.ua/hist/granatarif.shtml
The author (clearly with some military experience) says, that 200 m safe radius from a manual must be a sure safe radius, multiplied by 2 for greater certainty. At 50-70 m there were found fragments, but only big ones, like 1/4 of shell.
A probable field of hitting fragments is 78-82 sq.m - some 5 m radius.
All in all, it seems to me, that grenades are not that efficient, as raw figures say, and probably it concerns most grenades, not only F1.
Michal