This is a key reason why I don't bother with computer dive logging but rely on old-fashioned paper logging instead. As an instructor, I end up doing a whole lot of little dives to set up and break down equipment. As a technical diver I often do similar dives. For example, last weekend I did 5-6 "dives" setting up ascent/descent lines, staging decompression bottles, picking up spent bottles, etc. My computer considers each one a separate dive; I don't. If I were to use the computer dive log, I would have to take the time to go in and override everything manually, which is a PITA. I prefer to open my log book at the end of the day and jot down what I did in a way that makes sense to me.
The Rescue Course is one of the rare moments when the students have the same problem. You just combine several dives in a way that makes sense. PADI says to combine things into two dives. If that makes sense to you, then go with it.
On the other hand, if it does not make sense to you, do something else. It's YOUR logbook. There are no laws involved. The scuba police are not going to go over it like immigration officials inspecting the passport of a suspected terrorist. Do what is meaningful for you. It seems to me that what you did in your rescue class should be in the logbook in some way, but others may disagree. It's their right.