You're right, I wasn't thinking that the heroic tier came from Rag as well!
And chardev won't load for me atm, not sure why.
And haha, their look was also one of my concern when calculating which offpiece I wanted. I was glad it wasn't the one.
Something else : You're calculating BiS sets that almost make it unhittable (0.03% off), while using offpieces. You want to consider that while gathering that set up, you won't be unhittable. The 4 piece gets you unhittable 2/3 of the time. To me, it's not worth it to dodge it, especially like you say it, some items will be out of range, and sometimes, you'll just get very bad lucky on some items that won't drop (according to our guild luck with shields, we won't see a shield in the next 6 months..).