At the moment, all SRE cookbooks are installed to both production (cuminXXXX) and cloud (cloudcuminXXXX) cumin hosts. I think it would be nice to separate the cookbooks that are relevant to both production and cloud hosts (e.g. sre.hosts.reimage) to a separate "shared" collection that can be installed on all cumin hosts, while the "SRE" collection could be installed only on production cumin hosts and removed from cloudcumins.
This could evolve even further if other teams/sub-teams want to create their own cookbook collection in the future. The modular structure introduced in Spicerack 7 makes it easy to cherry-pick a list of cookbook repos you want to install on a specific host.