The order of material and deliverables matter in a course. You might follow the order found in the text book, the order you encountered it as a student, or the order that was used before for the course. Adopting an order may or may not make sense. Do not assume that it is appropriate for the course's learning outcomes or for the students you are teaching. You should do a thorough thinking exercise to make sure that the order is appropriate; more than a quick read and nod of the head.
While Tyler (1957) was describing curriculum at the secondary school level, many of his points from 1957 still resonate today, at all levels. A recommended read.
The order is a strategic decision and it can make up a fair bit of the difference between a good course and a bad one. It is necessary, but not sufficient.
The order impacts cognitive development at all levels. The way a topic is introduced matters and how the topics flow together matters. The order and flow impacts how much has to be digested, what is reinforced, what can be practiced, and the fundamentals of actual learning. Of course, if the course is nothing more than memorization, recitation, and robotic pattern matching; no need to worry about order. Order is probably not an issue if all you are worried about is what they can remember for the final. However, if you want them to actually comprehend, be able to apply and analyse with some level of independent thought, not just repeating what you told them, being able to cobble concepts and ideas together in new ways not discussed in class or the text, and be able to think about what they have done, evaluate what they have done, then order matters.
We have found it very useful to have a buddy to discuss the order and progression of material with. It is WAY too easy to make many invalid assumptions and overlook key bits. One of you should have more than a passing knowledge of cognitive skill development. If you do not, go get help and do a review with a teaching resource who does.