Well, I have it too, depending on settings. My theory is that attacks triggers new effects like sounds and animations that may not be available in RAM, so disk must be accessed, which is slower and causes a stutter. Some games precache effects they are about to be used when loading the battle map. I would certainly find it desirable to cache all the effects before playing the animation to provide smooth experience, but... you know. 

Its rare for me, but it happens when the projectile seems to have some sort of pathing threw an object, or hill, or something  -- i can't remember exactly.   There's probably some calculations for displaying it that are causing it to hang. 

Thanks for your willingness to help the cause of a great game.

It does not have to be related to sounds specifically, on my main gaming uber-rig, I have no stuttering at all, while on laptop, I have it all the time. 

There are many assets required to display the fighting animations - animations themselves, textures, sound effects, and they can be stored on various media with different access speed - hdd, ram, VRAM. What is desirable in what situation may be different on every configuration, sometimes VRAM is just too small, and the video card bus slows down the process, sometimes there is not enough RAM and disk must be used frequently. Optimization is no easy task.