Can a XML schema have mix and match of qualified and unqualified namespaces?

From what I know from W3school is that if the attribute "elementFormDefault" is set to unqualified on a XML schema then XML elements will not have prefixes. Can this be a problem if I have a schema that has unqualified element form set and am importing another schema?

Example: I have Schema A that imports Schema B's stuff. Then in a most unfortunate scenario Schema A has an element called "ItemName" in which Schema B also has one. And since we can't use prefix here, there is no easy way to distinguish both elements.

Is this a valid scenario?

if yes, how do I distinguish them?

And if yes, does that mean that a schema can have mix and match of elementFormDefault=qualified and unqualified namespaces living in it and not have potential element name clashes in them?

Thanks for your help!