When developing jobs on DABs, we use new_cluster to create a cluster for a particular job. I think it's a lot of lines and YAML when what I really need is a "small cluster" and "big cluster" to reference for certain kind of jobs. Tags would be on the job and get propagated to the cluster.

According to the dab-docs, we can create a cluster under resources: clusters: but surely we are not meant to use all-purpose clusters as a job cluster?

See the example here: https://docs.databricks.com/en/dev-tools/bundles/resources.html#cluster