Resolution: With multiple schemas with the same target namespace in a shared module, BW will report the error:
"Schema namespace collision in SharedModule. Multiple schemas with identical namespace [...] were found in shared module [EmployeeSharedModule]. Ensure schema namespaces are unique within a shared module."
The behavior is expected. BW 6.x does not support two docs sharing the same tns *in a shared module*. This is because importing docs, in app modules, cannot use a cross-bundle location to distinguish between the two docs with the same tns. But, two docs in an app module can have the same tns because importing docs can make use of a location attribute to distinguish between the two.
As a workaround, you can put all the schemas having same target namespace in the application module itself instead of the shared module.