I stand by 200k not being a big deal in a temporary situation for someone that only recently started playing.
400k is a lot more than I thought possible, can you show me some logs or sims?
Warcraft Logs - Combat Analysis for Warcraft
Only 2 ilvl difference between first and second Harjatan kill, and the first has shit legendaries, second has more or less ideal. 723k vs 1.16m. Ironically, I haven't been able to pull much more than that with even higher ilvl. It was all legendary. Hasn't applied to every fight, but I'm not exactly going to use less than ideal legendaries when I have ideal legendaries for specific fights (single target specifically), if that makes any sense. I've had IFE for a while, experimented with others, just doesn't make the numbers. IFE is super strong, OI is even more strong on AOE fights. Lady+OI, or SOTA+Lady on AOE are fairly similar. Prydaz, Sephuz, moon cloak, Chest, Boots, I always pull less than 1m.
TOS has also been pretty hard for me to maintain consistency. Have to swap gear, talents for literally every fight, and my damage for a particular week can tank if we have strong AOE in the group. Having Lady+OI has definitely been a huge benefactor in my AOE damage. Helm+IFE I've had for a while, and has been my best single target pairing.