I was raiding with them, we'd get 13/14, next week only 4/14, week after that 9/14 week after that 10/14, then 13/14 and it went like this over and over. I even told them to just extend the raid at 13/14 to kill garrosh, but nope, lets do a fresh raid every week and fuck up on those super easy bosses.
Oh and everyone in that guild was full normal geared only needing warforged gear, and some even killed garrosh and some had all the normal items they needed. I started with them when I had shitty timeless gear and 3-4 flex items, ended up only missing 1 trinket(lost 2 times on it) and a neck. It's been 5 months, still no Garrosh kill when average ilvl of the group was around 563+ probably.