Arcing/bracketing helped with determining what the main argument is. There is some overlay of the study methods. So the main-point in bracketing is often also the main argument in phrasing. Arcing/bracketing helped in how to arrange some of the phrases like a -/+ relationship. - If that does not make sense - don’t worry you’ll pick it all up eventually.
I usually do arcing and phrasing on all the passages I study. Depending on time though, I’m way more fluent in arcing and use it when there is limited time.
And yes, some methods are better for certain passages. Basically, a passage from Paul is usually focusing on arguments - hence phrasing. A narrative in the gospels is often a sequence of events - so arcing is a good choice. Having said that, I find that phrasing does the best job in visualizing any text.