About the last paragraph: Doesn't that only *seem* so?
Steps != turns. A step consists of a variable amount of turns, depending on the total speed of all actions you do in it (that's why for example enemies might attack you multiple times when you reload you chaingun).
I'm gonna explain it with an example (with fictional values):
Say that pistol 1 and pistol 2 both fire with a speed of 1 turn when they're not modded, that makes 2 turns for a dual shot.
Now say that if you attach an agility mod to pistol 1, it fires with a speed of say 0.75 turns, making 1.75 turns for a dual shot.
Both pistols fire in the same actual step, so you might think the second fires 0.75 too making 1.50, although in reality it DID take 1.75 turns. It took both only 1 step, but steps aren't a realistic representation of time.
Is that theory correct..?