Before I got the Pro version, I struggled with the same concept of arrangement within Rack itself. So I turned to trigger sequencers running on a divided clock. Here is an example of a patch driven completely by a sequencer, each trigger starts or stops a passage, or instrument:
Its a crappy old patch, but the concept is there. These days I prefer to “play” a patch, than to plan out when what must happen. Or I automate it all in a DAW. But that seems to take the magic away.
Have fun exploring. . .