Weapons and Abilities giving animation to character: Best practices?

Hi, I am delving into animation, and am trying to discover an extensible workflow.
If I have a humanoid character model, and possibly dozens of weapons and abilities, it does not make sense (to me) for this character to have an animation state for every ability and weapon.

Instead it would make sense for the weapon/ ability to have the animation data, and when the player equips or acquires it, the animation data is given to the character. I played around with IK Animation Rigging package, so each weapon could have its own "left hand" "right hand" position. It seemed promising, but also not as precise as regular animations for stuff like finger placement. (though that may be because I am new to IK, rather than that IK is imprecise)

Does anyone know if this is a viable design pattern, what any common "best practice" design patterns are, or can point me towards some references for extendable and scalable animation design patterns?