If SessionImp#cacheAccessStrategiesMap is changed so that the CacheDataDescription} is stored in the map value (along with {{RegionAccessStrategy), then if multiple entities are configured to use the same EntityRegion, then compatibly could be checked in SessionFactoryImpl.determineEntityRegionAccessStrategy. Hibernate could issue a warning (at least) or throw an exception when incompatible.

This obviously would not work if we are going to allow different types of regions to have the same name.