Now show me EVERYONE'S equipment from all groups who've done this fight in global.
Oh you can't?
The problem comes down to this fight being new.
If it's not the equipment then you're basically admitting that it's the skill level of the players. No run where the players have at least a decent level of skill / EQ should be longer than 20 min even if it's the first time of them doing it. Most of TPDs attacks are decently enough telegraphed to the player and the DPS checks people love to fail are pretty much just that. If Sodam gets to "clap his wings" then it's either people not having the gear or not doing their rotations properly as the boss is not trying to interrupt / evade your attacks, this has nothing to do with "the experience of the fight" as you don't need to memorize every inch of it in order to not do terrible here.