Maybe you should go by the levels when documenting your project?
While for the individual buildings the stories are ground, first, etc floors, on the site, what is one building's ground floor can very well be other's second floor.
If I did a project like yours (and I have done a few on very steep sites in my life) I would document like this:
the whole complex: plans at level 1, 2, 3, etc, from the lowest to the highest. The visibility should be OK.
each separate building: plans as normal, taking care that the levels are correct, so that it can corelate.
IMHO this is more a question of organizing your project than an Archicad problem. Or, a combination, where organizing is more important than the softare's features - or limitations, as the case may be ...
Djordje
ArchiCAD since 4.55 ... 1995
HP Omen