Core strength and hip rotation is important but not the only thing that improves velocity and accuracy. Now I am not a great athelete, but do play hockey and have been working with a trainer the past four months to improve my shot, velocity and accuracy. My core is not the problem and my latts have always been strong making for a pretty good heavy wrist shot which really isnt one. More a pull shot from my latts, hips and legs. Problem is I often dont have that time or space to get it off. So I have been working on my snap shot by doing a variety of wrist curls and working on forearm lifts. Its been paying big dividends. Able too roof the puck easier with more velocity. Sauce passes are more accurate and I can get a snap shot off, more wrist forearm action, quicker. Just saying there are multiple fundalmentals that make stronger arms than you listed. Depends on what is needed. Marino’s 60 yard flicks come to mind. Dude had amazing forearm wrist strength.