Yes, you could. HOWEVER -since they are the spines that introduce you to various countries and their people in a personal and interesting way and there are places to record written narrations specific to the MW and HP books, removing them from it would only leave a map drill book.
You could always add in other books about countries with that portion (although that would be A LOT more work and time than simply buying the spines). I think that your decision would depend on what is most important to you regarding a more personal planned approach to geography or a straight-forward ready-to-use map drill book with you adding in what books you can find. If you haven’t looked at the free sample pages in depth, I would recommend you do. It would make the decision easier for you.
IMO, these are spines used multiple years in multiple books for mulitple ages, so they will be worth their price in the end.