I would agree with you that it is important to teach the books in the suggested order. However, in Delaware, we give a State Performance test in the middle of March for grades 3, 5, 8, and 10. This test is the determiner for whether or not a student is promoted. Because this assessment is given before the year is even 3/4's over, we have had to change the order so that our students have covered those areas that they need in order to pass this test. It is not ideal, but it is posssible.
