This is why the movie is taking some time. Scenes like this require a lot of masking. Its best to mask limbs independently, which is why the droid is only partly there. A new back ground plate is also made. There a lot of people in this scene, each needing to be masked as such. (Rubble and fire is just a stand in for now and not final. Just feeling out the scene as i work on masking.)
The shadows are being made soft shadows to match the shots of when the Jedi are on the ground fighting. In which all the shadows are soft shadows.
There are many scenes like this, either with new back grounds, fixed shots, or modified shots (some shots are masked in different areas for blur/depth of field, color corrections, saturation, etc).
On top of masking out things, new back grounds have to be tracked properly into the shot. Plus compositing in new elements for scenes such as this, with rubble, ruin and fire.