From the JAX-WS specification section 3.6.2.1 regarding Document Wrapped: -

Conformance (Default wrapper bean names): In the absence of customizations, the wrapper request bean
class MUST be named the same as the method and the wrapper response bean class MUST be named the
same as the method with a "Response" suffix. The first letter of each bean name is capitalized to follow
Java class naming conventions.

Conformance (Wrapper bean name clash): Generated bean classes must have unique names within a pack-
age and MUST NOT clash with other classes in that package. Clashes during generation MUST be reported
as an error and require user intervention via name customization to correct. Note that some platforms do not
distiguish filenames based on case so comparisons MUST ignore case.

However if two services in the same package have the same operation there is an overlap of the generated wrappers which then causes the schemas between the two WSDLS to overlap.

Using the @RequestWrapper and @ResponseWrapper annotations does separate the wrappers which also corrects the WSDLs, from the JAX-WS spec 'Conformance' paragraphs above this conflict should have been identified and reported as an error during deployment.