I was thinking about this idea a lot the other day.
Currently I conceptualize the CMS like this: The creation of a collection creates a template (collection page). The Template then has to be used with that URL string. Unless the collection is for internal use then the generated template will remain blank and in the template list.
If we could create template pages independent of a collection then we could create designs that could fit multiple industries and flip the design on the fly for a new client. And it would allow us to create different sub-pages in the collection. This is very similar to the way Modx works and find it useful for larger sites.
When creating a page in the collection I imagine the only option would be to choose a template. Once the template is chosen the form fields that were set up for that template would appear.
Hope that's clear. It's clear in my head but hard to get out in writing.