Consider the following:

manifest.yml

policy_templates:
  - name: apm-server
    inputs:
      - type: apm
        vars:
          - name: name
            default: my-default-name
        template_path: ./agent/input/template.yml.hbs

agent/input/template.yml.hbs

name: {{name}}

There will be a clash between the name field in the template (package-defined) and the name field in the input (spec-defined)

Same thing occurs for data streams templates. This scenario should be detected and avoided.