Easy way to combine a bunch of separate PDF's into one file?

Open all the PDF's at the same time that you would like combined together in Preview. Once opened, hit CMD+P. This will open your print dialogue box. In the bottom left corner you will see a PDF option you can click on. Click on it and then Save As PDF. Easiest way I know other than owning Acrobat Pro. Screenshot below.

 

You can also drag and drop in the Preview Thumbnail view to arrange pages, delete pages, and insert pages.

 

I have a question about combining multiple (numbered) files using Acrobat Pro "Combine Files" option.

Selecting numbered pdf's. NOTE check the 01-02-03 numbering



But adding the selected files in the Acrobat dialog using "Adding Files" I get the following sorting of the numbered files:


Resulting in a combined PDF file with screwed-up numbering so I have to manually rearrange the pages 02 to 09. Is there an option to change the way Acrobat handles file numbering?

TIA & Cheers