How do exactly the "fire more Arrows" from Strafe + Decoy work?

Hi

Some links, like
https://classic.battle.net/diablo2exp/s ... sive.shtml
tells that

Strafe will fire more

Arrows if you have a

Decoy out which is another good reason to use

Decoy.

How do this exactly work?
(How many extra

Arrows?)
(Are the extra

Arrows shot in the end - increasing the attack length or are they shot between the regular

Arrows ?)
(How do IAS interact with the extra

Arrows?)
(Do the extra

Arrows do the same damage and have the same characteristics of the regular

Arrows?)
(Do

Decoy/

Strafe level affect the extra

Arrows?)