In addition to writing, I’ve been doing more research into story structure.
The problem is, my story doesn’t quite fit the standard model, as each of the three character arcs is well-formed enough to have its own introduction-conflict-resolution — but not at the same points in the overall story. I think I can strengthen each character’s arc to be more of a solid story, though.
As with all writing advice, I’m going to let it sink in and discard what doesn’t apply.
I also may have too many scenes that are too short. I’ll be looking at scene structure over the next month.