It sounds like you must have tapped into some professional software, which is not really available for ordinary people - only the corporate animation business, which can afford it.
I tried searching for Puppet Creator and Crazy Talk Animation. I thought maybe I could find out what is needed, and then we would know if Inkscape could help. But I couldn't find either one. Do you have links? Do they have free trials, so we could investigate?
Certainly Inkscape can be used to make sprite sheets, though.
Possibly Blender could help - it's 3d modelling program (open source, and free).