Reusing Locally Defined Element in the Same parent Tag using "ref" ?

hi,

For the Snippet below :

<xs:complexType name="Team">
    <xs:sequence>
        <xs:element name="Name" type="xs:string"/>
        <xs:element name="Size">
            <xs:simpleType>
                <xs:restriction base="xs:integer">
                    <xs:totalDigits value="1"/>
                </xs:restriction>
            </xs:simpleType>
        </xs:element>
        <xs:element name="teamLeads">
            <xs:complexType>
                <xs:sequence>
                    <xs:element ref="Size"/>
                </xs:sequence>
            </xs:complexType>
        </xs:element>
    </xs:sequence>
</xs:complexType>


The element "Size" has local scope , Why Can't it be reused locally?
Usually in Programming Languages , a local element is accessible in
its complete Local Scope.Why isn't it implemented the same way
here?(i.e Why is "Size" not referenceable inside the whole "Team" Tag
)


Thanks