Im Automator gibt es auch eine Funktion um pdf's zu kombinieren. Vielleicht ist dieses Ergebnis ja kleiner. Die englische Anleitung
dazu lautet wie folgt (habe ich einmal irgendwo im Netz gefunden:
Combine multiple PDFs
Say you have a series of PDFs of various recipes, organized by type. Each is a separate file, but you’d like to combine them into one PDF. Prior to 10.4, you could use a third-party tool or a Unix program to get the job done. With 10.4, you just need Automator.
In Automator’s Library column, click on Finder, and then drag Get Specified Finder Items from the Action column into the Workflow area on the right of the Automator window. Next, drag the Sort Finder Items action into the Workflow area, below the already-placed action. If you don’t want to sort by name, click on the pop-up menus to choose another criterion and sort order. Click on PDF in the Library column, and then drag Combine PDF Pages from the Action column and place it at the bottom of the Workflow area. Select the Finder in the Library column again, and drag the Open Finder Items from the Action column to the bottom of the Workflow area. When you’re done, you should have four actions (see screenshot).
To turn this Automator action into something you can use directly from the Finder, choose File: Save As Plug-In. In the window that appears, give your action a meaningful name (Combine PDFs, for instance). Leave the Plug-in For pop-up menu set to Finder, and click on Save.
To put it to use, quit Automator and switch to the Finder. Select each of your PDFs, using the shift and/or Command keys as necessary to select them all, and then control-click on one of the selected files. Choose Automator: Combine PDFs (or whatever you called it) from the pop-up menu; then just sit back and wait a bit. Depending on the size of the PDFs, and how many PDFs you chose, the process will take from a few seconds to a few minutes. But when it’s done, Preview will open one document containing every PDF you selected. Select File: Save to save it to the location of your choice. Note that this works best for PDFs with identical or very similar page layouts. For instance, you won’t get good results if you combine landscape- and portrait-mode PDFs.