The benefit to the Jardines
are the headers ... They still go into a single collector yes, but that's a good thing for "drawing" out the gasses. Headers are designed to allow a smooth/undisturbed flow of exhaust gasses, AND the collector they converge into, uses the gas being forced down one pipe to actually "pull" it from the others between cylinder firings.
The manifold design the bikes come with just works like a water pipe, it's only purpose is to direct/contain the flow rather than help to draw it out.
Is that any help answering your question, or just confusing?
I think the ideal set-up would be TOR's cans mated to Jardine headers, not too loud, not too quiet. I'll bet that would sound good too.