Passing Xml Snippet into xslt as parameter

A current problem I am trying to solve is generating a comparison of two xml files with differences and similarities via xslt.

For example the first xml file looks like

<?xml version="1.0" encoding="utf-8" ?>
<Stats Date="2011-01-01">
  <Player Rank="1">
    <GP>39</GP>
    <G>32</G>
    <A>33</A>
    <PlusMinus>20</PlusMinus>
    <PIM>29</PIM>
    <PP>10</PP>
    <SH>1</SH>
    <GW>3</GW>
    <Shots>0</Shots>
    <ShotPctg>154</ShotPctg>
    <TOIPerGame>20.8</TOIPerGame>
    <ShiftsPerGame>21:54</ShiftsPerGame>
    <FOWinPctg>22.6</FOWinPctg>
  </Player>
</Stats>

The second file looks like

<?xml version="1.0" encoding="utf-8" ?>
<Stats Date="2011-01-01">
  <Player Rank="2">
    <Name>John Smith</Name>
    <Team>NY</Team>
    <Pos>D</Pos>
    <GP>38</GP>
    <G>32</G>
    <A>33</A>
    <PlusMinus>15</PlusMinus>
    <PIM>29</PIM>
    <PP>10</PP>
    <SH>1</SH>
    <GW>4</GW>
    <Shots>0</Shots>
    <ShotPctg>158</ShotPctg>
    <TOIPerGame>20.8</TOIPerGame>
    <ShiftsPerGame>21:54</ShiftsPerGame>
    <FOWinPctg>22.6</FOWinPctg>
  </Player>
</Stats>

When I embed the second file into the xslt file the output works as expected:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output omit-xml-declaration="yes" indent="yes"/>
  <xsl:strip-space elements="*"/>

  <xsl:param name="vrtfDoc2">
    <Stats Date="2011-01-01">
      <Player Rank="2">
        <Name>John Smith</Name>
        <Team>NY</Team>
        <Pos>D</Pos>
        <GP>38</GP>
        <G>32</G>
        <A>33</A>
        <PlusMinus>15</PlusMinus>
        <PIM>29</PIM>
        <PP>10</PP>
        <SH>1</SH>
        <GW>4</GW>
        <Shots>0</Shots>
        <ShotPctg>158</ShotPctg>
        <TOIPerGame>20.8</TOIPerGame>
        <ShiftsPerGame>21:54</ShiftsPerGame>
        <FOWinPctg>22.6</FOWinPctg>
      </Player>
    </Stats>
  </xsl:param>

  <xsl:variable name="vDoc2" select=
  "document('')/*/xsl:param[@name='vrtfDoc2']/*"/>

  <xsl:template match="node()|@*" name="identity">
    <xsl:param name="pDoc2"/>
    <xsl:copy>
      <xsl:apply-templates select="node()|@*">
        <xsl:with-param name="pDoc2" select="$pDoc2"/>
      </xsl:apply-templates>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="/">
    <xsl:apply-templates select="*">
      <xsl:with-param name="pDoc2" select="$vDoc2"/>
    </xsl:apply-templates>

    -----------------------

    <xsl:apply-templates select="$vDoc2">
      <xsl:with-param name="pDoc2" select="/*"/>
    </xsl:apply-templates>
  </xsl:template>

  <xsl:template match="Player/*">
    <xsl:param name="pDoc2"/>
    <xsl:if test=
   "not(. = $pDoc2/*/*[name()=name(current())])">
      <xsl:call-template name="identity"/>
    </xsl:if>
  </xsl:template>

  <xsl:template match="Name|Team|Pos" priority="20"/>
</xsl:stylesheet>

when using the following c# code:

private string Transform(string xml, string xml2, string xsl) {
            StringWriter writer = new StringWriter();
            XslCompiledTransform t = new XslCompiledTransform(true);
            XsltSettings settings = new XsltSettings(true, false);
            XmlTextReader xmlReader = new XmlTextReader(xml);

            XmlTextReader xslReader = new XmlTextReader(xsl);
            t.Load(xslReader, settings, null);

            t.Transform(xmlReader, null, writer);
            return writer.ToString();
        }

When I remove the embedded xml from the xslt

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output omit-xml-declaration="yes" indent="yes"/>
  <xsl:strip-space elements="*"/>

  <xsl:param name="vrtfDoc2" />

  <xsl:variable name="vDoc2" select=
  "document('')/*/xsl:param[@name='vrtfDoc2']/*"/>

  <xsl:template match="node()|@*" name="identity">
    <xsl:param name="pDoc2"/>
    <xsl:copy>
      <xsl:apply-templates select="node()|@*">
        <xsl:with-param name="pDoc2" select="$pDoc2"/>
      </xsl:apply-templates>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="/">
    <xsl:apply-templates select="*">
      <xsl:with-param name="pDoc2" select="$vDoc2"/>
    </xsl:apply-templates>

    -----------------------

    <xsl:apply-templates select="$vDoc2">
      <xsl:with-param name="pDoc2" select="/*"/>
    </xsl:apply-templates>
  </xsl:template>

  <xsl:template match="Player/*">
    <xsl:param name="pDoc2"/>
    <xsl:if test=
   "not(. = $pDoc2/*/*[name()=name(current())])">
      <xsl:call-template name="identity"/>
    </xsl:if>
  </xsl:template>

  <xsl:template match="Name|Team|Pos" priority="20"/>
</xsl:stylesheet>

The change the c# method to

private string Transform(string xml, string xml2, string xsl) {
            StringWriter writer = new StringWriter();
            XslCompiledTransform t = new XslCompiledTransform(true);
            XsltSettings settings = new XsltSettings(true, false);
            XmlTextReader xmlReader = new XmlTextReader(xml);

            XmlDocument doc1 = new XmlDocument();
            // populate as needed e.g.
            doc1.Load(xml2);

            XmlTextReader xslReader = new XmlTextReader(xsl);
            t.Load(xslReader, settings, null);

            //Pass parameter value to xslt from code
            XsltArgumentList argumentList = new XsltArgumentList();
            argumentList.AddParam("vrtfDoc2", "", doc1);
            t.Transform(xmlReader, argumentList, writer);
            return writer.ToString();
        }

I get a blank output from the transform, for the life of me I can't understand why. I've stepped through both versions using the debugger and the parameter value looks identical in both occassions but when the parameter passed version hits the following snippet in the xslt no transform occurs:

<xsl:apply-templates select="$vDoc2">
      <xsl:with-param name="pDoc2" select="/*"/>
    </xsl:apply-templates>
  </xsl:template>

  <xsl:template match="Player/*">
    <xsl:param name="pDoc2"/>
    <xsl:if test=
   "not(. = $pDoc2/*/*[name()=name(current())])">
      <xsl:call-template name="identity"/>
    </xsl:if>
  </xsl:template>

Any help or suggestions would be much appeciated.