Does recount do a thing where it doesn't count numbers correctly or something?
Because I haven't played since the original Cata launch raids. I picked up the MoP trial, did the first zone, so I'm in quest greens. I did all the 5-mans I missed: ZG, ZA, and the 3 time-travel Heroic Cata dungeons, then the 2 normal MoP dungeons it'd let me queue for (temple and brewery). Except for the people I ran ZG and ZA with, I ranged from "crushing it in #1" to "In #1 by a decent margin". That's having never seen the dungeons before, not reading up on them in the slightest, just doing my work, standing out of the fire, etc. Some bosses took a minute to figure out what was going on for me and I made some mistakes, but I still never died. Maybe 2 or 3 other people total across all LFG groups got a "first run" achievement besides me.
Are LFG people really this bad? I had no special gear, no knowledge, and obviously all of them had ran it before on some toon or another. According to Noxxic, shadow priests are even pretty shitty this expansion, overall. I was top DPS typically for both damage done overall and damage done on bosses.