People who have a problem with the ark in general are just letting their bias cloud their judgement. It's incorrect to call the beginning of the battle filler, every battle has to have a starting point and necessary overview as to why and how it gets resolved. Otherwise you just have, and are in the middle of, fighting with no explanation or context whatsoever. Asking to rush that is just bad story telling, and the only reason people seem to have to problem with that kind of illogical jump forward is because they don't like the arc in general and are simply letting their biases shoot off weak criticisms now. Other aspects of the story may legitimately bother you but this chapter in particular is not one of them because EVERY story that has a major battle HAS to do these kinds of expositions unless you want to ask god to bend time and space to speed up the emptiness in your lives while you're at it.