Well, spoken, despite players challenging each other to ditch the schematics in order to make subsequent playthroughs tougher, the canon storyline would have Squall 'n' co. junctioning Eidolons to the point of ridiculosity and Cloud's crew would be sporting the best materia they could acquire without venturing far out of the way on Chocoback. The premise of junctioning Eidolons supports the idea of being able to usurp the very power of a "god-like" entity as the sorceress. The premise of equipping materia grounds the idea of being empowered by the Planet itself against a powerful creature like Sephiroth or Jenova or its own WEAPONS. Truth be told though, I don't really remember much about IX and still really don't understand how Trance exists.