Unable to create soap request based on different child types

[rohit1212s]

I am trying to create a soap request based on differnet type as below but not able to achieve that .Could you please help me on this issue if you can.
if you see the below in Example1 " <req:order xsi:type="req:derivativeOrder" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">" it can be different type based on requirement but by using soa model class it is only generating default request as below in example2:

Example1:-

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:req="http://www.able.eu/Epos/Ordering/PreOrderCheck/Request" xmlns:ser="http://syntel.nl/Epos/Common/ServiceContext" xmlns:shar="http://www.able.eu/Epos/Common/SharedObjects">
   <soapenv:Header/>
   <soapenv:Body>
      <req:PreOrderCheckRequest>
         <ser:productServiceContext>
            <!--Optional:-->
            <ser:conversationId>?</ser:conversationId>
            <!--Optional:-->
            <ser:deviceTypeId>?</ser:deviceTypeId>
            <!--Optional:-->
            <ser:entityId>?</ser:entityId>
            <!--Optional:-->
            <ser:advisor>
               <ser:id>?</ser:id>
            </ser:advisor>
            <!--You have a CHOICE of the next 2 items at this level-->
            <ser:product>
               <ser:id>?</ser:id>
            </ser:product>
            <ser:account>
               <ser:id>?</ser:id>
            </ser:account>
            <!--You have a CHOICE of the next 2 items at this level-->
            <ser:user>
               <ser:id>?</ser:id>
               <!--Optional:-->
               <ser:type>?</ser:type>
            </ser:user>
            <!--1 to 2 repetitions:-->
            <shar:externalUser>
               <shar:externalId>?</shar:externalId>
               <shar:type>?</shar:type>
               <!--Optional:-->
               <shar:advisor>
                  <shar:externalId>?</shar:externalId>
                  <shar:type>?</shar:type>
               </shar:advisor>
            </shar:externalUser>
         </ser:productServiceContext>
         <req:order xsi:type="req:derivativeOrder" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <req:cashAccount>
      <req:accountNumber>?</req:accountNumber>
      <req:accountType>
         <req:id>?</req:id>
      </req:accountType>
      <req:currency>
         <req:id>?</req:id>
      </req:currency>
   </req:cashAccount>
   <!--Optional:-->
   <req:distributionChannel>
      <req:id>?</req:id>
   </req:distributionChannel>
   <req:kind>
      <!--Optional:-->
      <req:limitPrice>?</req:limitPrice>
      <req:symbol>?</req:symbol>
   </req:kind>
   <req:quantity>?</req:quantity>
   <req:securitiesAccount>
      <req:accountNumber>?</req:accountNumber>
      <req:accountType>
         <req:id>?</req:id>
      </req:accountType>
   </req:securitiesAccount>
   <req:instrument>
      <req:instrumentKey>
         <!--Optional:-->
         <req:exercisePrice>?</req:exercisePrice>
         <!--Optional:-->
         <req:expiryDate>?</req:expiryDate>
         <!--Optional:-->
         <req:optionType>?</req:optionType>
         <req:symbol>?</req:symbol>
      </req:instrumentKey>
      <req:code>?</req:code>
      <req:orderTransactionType>
         <req:symbol>?</req:symbol>
      </req:orderTransactionType>
   </req:instrument>
</req:order>
      </req:PreOrderCheckRequest>
   </soapenv:Body>
</soapenv:Envelope>

Example2:--

< s11:Envelope xmlns:s11='http://schemas.xmlsoap.org/soap/envelope/'>
  <s11:Body>
    <sch56:PreOrderCheckRequest xmlns:sch56='http://www.able.eu/Epos/Ordering/PreOrderCheck/Request'>
      <sch4:productServiceContext xmlns:sch4='http://syntel.nl/Epos/Common/ServiceContext'>
<!-- optional -->
<!-- Pattern: \S.*, Min Lenght: 1, Max Length: 128 -->
        <sch4:conversationId>???</sch4:conversationId>
<!-- optional -->
<!-- fraction digits: 0, maximum number of digits: 4 -->
        <sch4:deviceTypeId>???</sch4:deviceTypeId>
<!-- optional -->
<!-- Pattern: \S.*, Min Lenght: 1, Max Length: 20 -->
        <sch4:entityId>???</sch4:entityId>
<!-- optional -->
        <sch4:advisor>
<!-- Pattern: \S.*, Min Lenght: 1, Max Length: 30 -->
          <sch4:id>???</sch4:id>
        </sch4:advisor>
        <sch4:product>
<!-- fraction digits: 0, maximum number of digits: 15 -->
          <sch4:id>???</sch4:id>
        </sch4:product>
        <sch4:account>
<!-- Pattern: [A-Za-z0-9]*, Min Lenght: 1, Max Length: 34 -->
          <sch4:id>???</sch4:id>
        </sch4:account>
        <sch4:user>
<!-- Pattern: \S.*, Min Lenght: 1, Max Length: 45 -->
          <sch4:id>???</sch4:id>
<!-- optional -->
<!-- possible value: EXTERNAL_ID, possible value: LOGIN_ID -->
          <sch4:type>???</sch4:type>
        </sch4:user>
<!-- from 1 to 2 -->
        <sch2:externalUser xmlns:sch2='http://www.able.eu/Epos/Common/SharedObjects'>
<!-- Pattern: \S.*, Min Lenght: 1, Max Length: 45 -->
          <sch2:externalId>???</sch2:externalId>
<!-- possible value: EXTERNAL_1, possible value: EXTERNAL_2 -->
          <sch2:type>???</sch2:type>
<!-- optional -->
          <sch2:advisor>
<!-- Pattern: \S.*, Min Lenght: 1, Max Length: 45 -->
            <sch2:externalId>???</sch2:externalId>
<!-- possible value: EXTERNAL_1, possible value: EXTERNAL_2 -->
            <sch2:type>???</sch2:type>
          </sch2:advisor>
        </sch2:externalUser>
      </sch4:productServiceContext>
      <sch56:order>
        <sch56:cashAccount>
<!-- Pattern: [A-Za-z0-9]*, Min Lenght: 1, Max Length: 34 -->
          <sch56:accountNumber>???</sch56:accountNumber>
          <sch56:accountType>
<!-- fraction digits: 0, maximum number of digits: 4 -->
            <sch56:id>???</sch56:id>
          </sch56:accountType>
          <sch56:currency>
<!-- Pattern: [A-Za-z]*, Min Lenght: 1, Max Length: 4 -->
            <sch56:id>???</sch56:id>
          </sch56:currency>
        </sch56:cashAccount>
<!-- optional -->
        <sch56:distributionChannel>
<!-- fraction digits: 0, maximum number of digits: 4 -->
          <sch56:id>???</sch56:id>
        </sch56:distributionChannel>
        <sch56:kind>
<!-- optional -->
<!-- fraction digits: 4, maximum number of digits: 15 -->
          <sch56:limitPrice>???</sch56:limitPrice>
<!-- possible value: AGIO, possible value: ALL_OR_NONE, possible value: DISAGIO, possible value: EVEN_MONEY, possible value: LIMIT, possible value: MARKET, possible value: MARKET_ON_OPENING, possible value: MARKET_TO_LIMIT, possible value: MUST_BE_FILLED, possible value: STOP_LIMIT, possible value: STOP_LOSS -->
          <sch56:symbol>???</sch56:symbol>
        </sch56:kind>
<!-- fraction digits: 4, maximum number of digits: 10 -->
        <sch56:quantity>???</sch56:quantity>
        <sch56:securitiesAccount>
<!-- Pattern: [A-Za-z0-9]*, Min Lenght: 1, Max Length: 34 -->
          <sch56:accountNumber>???</sch56:accountNumber>
          <sch56:accountType>
<!-- fraction digits: 0, maximum number of digits: 4 -->
            <sch56:id>???</sch56:id>
          </sch56:accountType>
        </sch56:securitiesAccount>
      </sch56:order>
    </sch56:PreOrderCheckRequest>
  </s11:Body>
</s11:Envelope>

In this example2 Order tag is not getting implemented by different type.