I had to take the time to create the Automator workflows, which was a bit of a pain, but it worked so well (and it let me just run the workflows in the background) that it was worth doing it.
I'm not sure why either effect should have resulted from using Automator, but I can't argue with the successful results. The crazy thing is that the inactive memory problem was eliminated when I used an Automator workflow to create the ZIP files. That's quite a MIS-management of memory I have 32GB of RAM installed in my Mac Pro Quad-Core. It chewed up active memory, turning all the 'green' memory (as displayed in Activity Monitor) into 'blue' memory.at which point everything slowed to a crawl, the Mac became unusable, and I'd have to reboot. There was another problem with using Archive Utility manually, which I didn't mention in my earlier post.
Actually, I solved my problem a different way by using Automator in conjunction with the Archive Utility.
