One thing which would be interesting to look at is how much configuration can actually be shared between a DataGrid and JEE server-group.
I mean if it's just the domain name, then it's rather a grouping feature which is most probably easier to do on a aggregation level (JON) than in the domain model itself. Where you would also be able to share a domain across multiple groups.
Also based on this we could also see if multi-tier should be done in one domain, where you cannot really share a server-group between different domains. Or if a hierarchical domain would be a better approach trying to solve this common configuration.