So... either Sch doesn't use their kit or Ast doesn't use their kit. What is the point of having Ast with nocturnal at that point? It would be far more beneficial to a team to have healer with regen and a separate healer with shields than have two shield healers with one being unable to use gcd heals. What happens when a run starts to go sideways? You are sitting there stuck with one healer unable to spam their aoe because, you know, shields don't stack. Unless you solely do normal content, this would be massively unfeasible and I don't see any group that would be willing to do it. SGE/SCH works because SGE has the capability to spam heals that aren't shields should the need arise (even if they are a weaker version of medica I or helios). I don't understand this take.
And how is SGE a copy pasta of AST with nocturnal? Because they can shield and have a regen skill? SGE is equipped with more mitigation than AST, has a reapplying shield (Panheima), and a laser cannon that heals the party not to mention a ton of other abilities the AST doesn't have as well as AST skills that the SGE does not have. SGE is the dps healer. AST is the pre-planning healer. Just because a few of the abilities are slightly similar does not make them copies.