@Goatmaster3000 It’s not difficult. If you only want to modify SSI’s aiming speed, You can apply doctrine effects on humans directly by adding a <Doctrine name="NodeName"/> in the Entity/Human template xml. See the SWAT Leader template. For an example, Add a Doctrine skill to SSI which originally enhanced the Rangers' aiming speed. Alternatively, you can create a custom Doctrine skill and add it to the entity files. You could also modify the attacktypes of the weapon used by the unit individually—but personally, I find the former approach simpler and more convenient.

@Goatmaster3000 funnily enough, you have to edit the weapon stat improve aim speed for a unit

If I may ask, what is the thing you need to edit in the entities file to improve aim speed for a unit?