Later in the film after Hosnian Prime is destroyed, we could have a montage of establishing shots of notable planets where we see one or multiple Destroyers arriving at each world. You wouldn’t have to necessarily depict any battles, but this could visualize the idea that the First Order basically blitzkriegs major systems as it simultaneously destroys the Senate. If it disrupted the flow of TFA’s climax, this montage could potentially be included at the beginning of TLJ instead.
I dig this idea. Also, knowing how a lot of TROS fan edits have cut out the Kijimi destruction footage, editors could now use some of that footage to show how FO Star Destroyers are blitzkrieging worlds.