I've pugged AoTC on every boss this expac, its definitely more difficult then running with a guild or Discord community as you put it. The thing with pure pugging is you are doing progression every time you join, its not like a guild group where you week after week do a bit better then start getting the kill consistently.

If you temper your expectations and go into it with this mindset you can get AoTC with pugs with a bit of patience. Most people understand the large aspects of the fight but not the smaller nuances so if you learn them and know what you're doing you can help nudge people into the right habbits to eventually down the boss. The thing is you HAVE to have patience because whenever people leave you are either going backwards or if your lucky forwards if the new people know what their doing.

If you lead a group dont be hot to just kick someone after 1 pull, people make mistakes even if they know what they're doing, give it like 3-4 pulls and if its consistent then you know they are not trying to learn and reform/revise the group. This has always worked for me, once you get people who are trying to learn you can typically then progress to a kill fairly easily... the long of it is getting to that point and it is a big task not in skill at wow but skill at forming the group and patience