Please merge both documents in a file that contains the pages in order
The pages could be either odd or even number in total, but the odd pages should be first and more or equal the even pages for the below to work properly.
In it copy and paste this code:
for (i = 0; i < ((this.numPages - 1)/2); i++)
then press the green triangle to execute it, and your pages should now be ordered properly.
All that's left now is to save the document with the reordered pages.