I've been riding horses a long time...
Never bothered me...
I of course,have not had occasion to ride them into battle...
Or for months/years at a time...
I can pull a 40 lb bow....
It hangs proudly over my fireplace...
This woman is Acadian/Native American....
Maybe I am missing your point...
What's the issue?
Historical?
Ms.B
To use a bow effectively you have to be able to pull it easily enough to aim it; it has to be steadied on a target before released.
Most grown men cannot use a 70-lb bow. Most American hunting bow manufaturers don't even make anything over 70-lbs other than special order. Most English longbows were 70 or 80 lbs and you can be sure that English yeamen were at least as large and strong as Mongols.
The claim in this article that Mongols all used 160-lb bows is basically a flight of fancy.