Having Animations_Affect only part of static mesh?

Hello there, I have a question regarding how you would go about the problem I have:
I procured a static mesh from the internet which is divided into bones, with no animations at the moment. My goal is as follows:

I have 4 basic movement states: running, jumping, idle, and falling.
However, I wish to be able to, for example, throw a strike (such as a chop, punch, etc) in an animation that affects the arms alone, and if the player is not striking, to employ arm animations that
I will define as to be used on the above states (ex. If he isn’t striking, he is moving his hands back and forth while running, or raising his arms if falling. If he is striking, the punch animation is played on the arms, but the rest of the body is still running).

Is the best way to go about it to somehow split my model and bones into different pieces (ex. Body and arms), animate each individually(body animation for the 4 states, arms for the 4 states and all strikes), and recombine them together(hence the title.)?(I have not used blender or any other animation technology at this point, so forgive me if this is an unreasonable rout or impossible). Or would you go about it in a different way? Thank you for your informative responses!

I am not proficient with anims but have messed with it , you should be able to use like a blend pose node or more specific , layered blend per bone nodes , where you can tie two anims into one ; or additive anims. Take a look at the link in this thread. Or the lower explanation , should point you in the direction.…ying-animation

Or here as well.

Thank you very much! This seems to be what I was looking for. Have a good day!