You can change the firing angles of the weapons. So you might not need to change anything else in the collimation section.

In the WoP3 Spitfire, they were shooting too high, so I decreased the angle from -0.039 to -0.017:

<Station name="Nose" params="0,9,0,0,-0.039,0,200" /> <- Default angle

<Station name="Left Wing Outer" params="-4.0,0,-0.5,0,-0.017,0,200" /> <- Spitfire angle

I did that so the bullets/missiles/rockets are heading towards the center of the gun site (that is included in the WoP3 Spitfire) and when I aim at an object to destroy, they will head straight towards it and not over the top of it