Actually what might be better is sheet functions. So like pages where you can define input and output cells. Then you top level sheet can invoke the "function"

Actually what might be better is sheet functions. So like pages where you can define input and output cells. Then you top level sheet can invoke the "function" as like "=mypage(A1, A2).N8". That way you get local scope, etc, and even excel noobs could figure it out because it's very visual instead of being a mathematical function.