Print Everything in One Job
Printing several PDFs separately means juggling print dialogs and risking pages coming out in the wrong order. Merging them into one correctly-ordered file means a single print job, the right sequence, and no missed documents.
Order It Once, Print It Right
Arrange the files before merging so the combined PDF prints exactly as intended; pair it with the N-up tool afterwards if you want multiple pages per sheet to save paper.