This is perfect, I just did this a few hours ago on one of my projects. What I did was disable the default animations completely by just making a localscript called “Animate” inside StarterCharacterScripts to override all the default animations. I then attached a weapon (model) to the character upperTorso with a Motor6D object and simply animated all the character movements with that.
I found this very informational: How to animate Tool Parts (Guns, Knifes etc.)