big things to notice is how wide they spread sideways while extending. look how spread out the theurgists, clerics, sorc, cabby are. not a single ae, not even two ae's or three ae casts could cover them all.
theurgists are usally opposite sides hella wide so no one ae can send ice pets into combat or get nuked down. they run at angles so the petted tank cant just run at the ice pets while chasing the theurg to get snare broken. criss cross when needing to rr5 stacks.
theurgists dont put alot of ice pets in one area. theyre casting some and constantly moving to change positions so its harder to clear.
also notice the multitasking of arms from tank peeling, his panning, positioning during dd and how the paladin is off on the side interrupting support and casters slowing them down while dps'ing them down using the backstyle snare that has the stun followup.
everytime the enemy group hits sos, arms is hitting ddrr5 but hanging back away from the enemy peeler so he doesnt get slammed.
notice on the mid groups how theyre casting cl disease alot during the sos and ppl are getting sheared while in sos.