I would not put both files in at the same time. You know how when we install a new EP, and we make a back up? Well I keep a current back of my saves on my external hard drive at all times. Every night at the end of the evening, before I head to bed, I copy and update the file that is on that drive. Because in case I have any glitches or problems to show up like I did yesterday. I traveled to Egypt, and when she returned, the 2 kids were unselectable and Chris was no longer showing on his panel as married to Agnes, but she was showing as married to Chris.
The whole save was very glitchy. So I deleted that saves folder, copied the one that was on the external, and pasted in the file.