Mapping dev,test,qa,prod with hiera?

gistfile1.rb

# Idea being that %{env} is set to one of {dev, qa, test} but not set in prod.
# Prod values will be used where no env-specific data is set.
# Any ideas of different or better ways to do this? Is this tree too deep?

---
:hierarchy:
    - %{env}/%{variant}_%{role}_%{group}_%{location}
    - %{variant}_%{role}_%{group}_%{location}
    - %{env}/%{variant}_%{role}_%{group}
    - %{variant}_%{role}_%{group}
    - %{env}/%{variant}_%{role}
    - %{variant}_%{role}
    - %{env}/%{variant}
    - %{variant}
    - %{env}/common
    - common

:backends:
    - yaml
:yaml:
    :datadir: '/etc/puppet/hieradata'


So a tree of files could look like ..

.
├── common.yaml
├── dev
│   ├── common.yaml
│   └── rhel6_pg_external_vagrant.yaml
├── rhel6_pg_external.yaml
├── rhel6_pg.yaml
└── rhel6.yaml