"they're advocating orienting the entire ship, not merely using a shelter."

Read an article fairly recently about "some" GCR being localized, but beside that (don't know enough about it yet) GCR will be coming from all directions. As far as I know solar radiation ("cosmic rays"/high energy particles) are only significant during flare events.
A shelter solves solar events- and you will have good chance of having at least one in long duration flight to Mars- whereas protecting crew by orientation to solar flare "probably" won't be sufficent- you could instantly kill crew if not adequately sheilded during large flare.
So this means you probably going to need a shelter. Designing ship so you can turn into a solar flare event might very well be a good idea, but I don't think it would be the only solution you would use.