Rather than using vendor-specific extensions to XSLT 1.0, you would be better off using XSLT 2.0, for example in Saxon 8.9.
Then it's
<xsl:for-each select="person">
<xsl:result-document href="{name}.xml" method="xml">
</xsl:result-document>
</xsl:for-each>
Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference