A) The Longbow with it's very long length means that the archer can use his fingers rather than a strap or ring to pull the string like with a Mongol bow.
the reason is simple geometry: the Mongolian style of bow has a VERY steep "V" shape string when cocked, this cuts into the fingers, making it impossible to use only fingers for high strength bows, so a strap or ring had to be used, thus, they weren't that great
The supposed "super accuracy" of the Mongolian archers was a myth, as when you have hundreds of folk firing, well, you WILL hit
some poor twit in the head etc
B) The Lobgbow's arrows are much bigger and heavier thanthe Mongolian ones, thus, more impact force.
Please note form tests and skeletons, longbow hits shattered bones (even smaller bows), the impact energy itself is enough to stop you cold a lot of the time.
C) Aye, the .45 ACP is the most effective handgun cartridge, iirc 91% 1 hit stops. with 95% for buckshot and 99% for shotgun slug?
Big and slow is a much better manstopper, hence the British use of the infamous .455, or the reliability of a shotgun with buckshot.
On the other hand, the .44 magnum is ismply too damn fast.
However, the enormous size and speed of the .50 cal Browning machine gun bullet means there's rarely such a thing as a "flesh wound" with it (Flesh wounds form it are most often air shock burns as it passes very close) .50 Browning will blow limbs off or kill with hydraulic shock.
Arrows on the other hand, if they have broadheads are far more lethal than most bullets, as most gunshot victims survive, most knife or arrow wound victims do not, because bullets rarely cut arteries, broad bladed sharp weapons do (hence a Roman gladius was incredibly lethal as it was 3" wide stabbing blade)
D) Are you sure on the weights I read and impact energies? .02 KG versus .06 KG...??
Longbow war arrows are a fair bit heavier than typical "archery" arrow, iirc, and bullets, well WHICH bullet?

.22 LR is tiny, .50 HMG is enormous
form what I recalled I though such arrows had about the same impact energy as a .38 or 9mm? (I'm not sure on that though)
a .22LR has around 55 foot pounds and a 9mm around 300+ foot pounds of power.
(Man I wish we'd all been scoholed purely in metric, I cna only think in soem term sin foot pounds, stone, or feet/inches, lol)