First, we can say that it is asking whether the Declaration would be just as effective if all the sections were jumbled together. In other words, what if the Declaration started by saying that the king had quartered troops in the colonies, then said that all men are created equal, and then said the king had refused his assent to good laws. If this were the case, the Declaration would not be nearly as effective as it is. Good organization is important in any writing. The reader needs to be able to follow a coherent chain of reasoning. If the sections were jumbled, it would not be as effective.
Second, we can say that the question is asking whether any sections could be left out. Would the Declaration be as effective if it did not contain all the sections that it actually does? I would say that it would not, though I think that the third section is probably overdone. All of the sections are necessary. The first section tells the reader the purpose of the document (to tell why the colonies were rebelling). The second section lays out the political theory behind the rebellion, arguing that governments are illegitimate if they do not protect the rights of the people. The third section “proves” that the king’s government did not protect the rights of the people and was therefore illegitimate. If any of these three sections were completely absent, a major part of the Declaration’s argument would be missing. Therefore, I would argue that the Declaration would not be as effective if it did not have all the sections that it has.