Sure, they can get the mechanics down pretty easily. Heroic Lei Shen was a hilariously difficult fight with insane dps checks which hinged on dps getting their trinket procs at the start of the fight. (The RNG of static shock didnt help either) Given that most guilds didnt even get close to killing it until item upgrades became available (not to mention the VE target cap bug day one of 5.3), there technically isnt much room for many people to talk at all.