When to Use Micro Templates and When a Composite Template?
If you use a single composite template to provision a very large environment, the composite template could get very long and complex. In such cases, you can split the composite template into layers, define a micro template for each layer and create a product stack out of the layers to use for provisioning your environment.
A composite template works best when you want to use a single template from which you create different environments, using external environment properties files for each type of environment (development, test, and production).