Sorry but in this case it's kind of true.
While Turn 1 and Turn 2 are execution checks, Turn 4 is a gear check. You need enough DPS to advance through the waves. While it's possible to make up for a lack of gear with exceptional skill and squeeze out more DPS than the average party, most groups won't be downing Turn 4 until they have a couple weeks of gearing in, and their Relics+1 on DPS. Turn 5, similarily, is a mix of a gear check (having the highest HP pools possible certainly helps survive the punishment) and unforgivingly perfect execution, along with, unfortunately, luck, in terms of not being screwed over by the RNG.
