That's what we do with most things in general in powerscaling. So, when looking at the situation and the two claims (
the Tenseigan did/didn't move the halves back), you have two conclusions you can draw: 1)
the Tenseigan likely moved the halves back together such that it could more easily slam the whole moon into the planet or 2)
the Tenseigan likely didn't move the halves back together and the movie is just inconsistent.
I obviously support conclusion 1. Not only is it the only conclusion that follows that doesn't create a needless contradiction, there's no reason to discredit the assumption. Why would the animators draw key attention to a scene that has the entire intention of displaying Toneri's power if it's just wrong? You can't reconcile it without assuming the animators are just stupid and don't know how to properly portray what they are animating. I believe most people will see eye to eye with me on this, if
this thread is any indicator of how we should treat sizes. The majority of staff agree that scenes in which "large sizes" (in this case the intentional depiction of Toneri's feat) are the focal point are better than scenes in which "smaller sizes objects" (in this case the peeps chatting) are the focal point.