There isn't a specific name for them, because they create everything by hand — editing movements and matching rhythms themselves when making their works. Such creators are quite rare.
Currently, due to programs like KK (Koikatsu), HS2, and VMA, as long as you can find scene data (SD), you can basically replicate animations — choose your own main character, record each action for about a minute from different angles, then switch to another SD. By copying and pasting like this, you can easily become a "replica creator."
KK (Koikatsu), HS2, and VMA themselves aren't bad; it's just that 99.9% of people who use them are only using the content, while only about 0.01% actually create original scenes. But even that 0.01% may not produce full works — they just sell scene data. So, watch and appreciate what's out there while it lasts.
