I find it more smooth to have my main attack on A on Xbox and the generator on Right Trigger. I started doing this on my Dance of Knives Rogue, with DOK on “A”, and now on my level 55 Spiritborn (if you can’t beat em, join em. Am I right? 
) I do the same with Quill on A.
Just random information but maybe I’ll help someone try a new style. Core skill on A also seems more fluid on builds that have no generator to help with looting on console. Basically you don’t want to use a cool down while trying to loot.
Anyway hope I helped.