Does the top pvp player set the /stopcasting macro and make a key-binding with that in the world of warcraft? Is it necessary? Or just move the character to break the casting spell?
Short answer: It depends.
- If you're simply trying to stop casting of a spell with no following action, then moving is just fine and is preferred so you don't waste a keybinding on doing essentially the same thing.
- If you want to stop casting as part of a macro that is going to do something else like "fire off an emergency heal", then using the /stopcasting command is better.