Just want to be clear, I am only a hobbyist, and definitely not an expert.
I know some like a longer arm for more flexibility in controlling where the light comes from, for example lit from the side, but in my own experience, I haven't found a need for long arms. It may have to do with my lamps having a wide beam (appx 90 degrees).
Do you find yourself fully extending the arms when you film ? If so, forget my comment and don't fix what isn't broken. If you rarely fully extend them, you might want to try shortening them. That might help keep the arms from moving.