All level 1 contents with a template, subpages with another one?

Hello again, I have 6 folders in my content, and each folder have some subpages. Is it possible to assign the same template for all the 6 folders, and another one for the subpages (default.php for example)? For now I only see the possibility to have multiple copies of the same template with different name matching each folders. But I get the feeling there is a smarter way to do it, thank you for pointing me in the right direction.

If they all use the same blueprint (i.e. identical text file name), yes.

If they don’t use the same blueprint, then why are they supposed to use the same template?

Thank you for your question! I didnt’ fully understand how blueprints work… (you are such a maieutic master)