Hey Julie,
You definitely have the right idea. If you are not going to use an external Tri-level sync generator, then you have to pic a MASTER, and set some SLAVES. In your instance I would probably use the Camera as the MASTER sync clock, and Jam the Denecke and the Audio Recorder to that Master Clock.
You technically should jam them all together, but the latency drift should be really, really small, if you do them back to back.
Naturally, I would check every 4 – 5 hours for any drift… If you have a location move or some down time, it's not a bad idea to Jam again.