There have been several requests for how they all work together.
This is the upgrade from the pre-mod world.
It might have been changed but this model is how it used to work and the big addition is the Mods, which are importantly calculated outside of the weapon/leader/misc multiplier.
(note: Weapon Mod = weapon buff)
also note a shield would be 50% defense buff vs the 40% one i’ve included, either way… .shields have monster DEF stats.