PLAIN:
{$subPosition = 0}
{foreach item=details key=position from=$sOrderDetails}
{if $details.swkweSetArticles || !in_array($details.modus, [20, 21])}
{if $details.swkweSetArticles}
{if is_array($details.swkweSetArticles)}
{$detailAmount = (!$additional.show_net) ? $details.swkweSetArticles['netAmount'] : $details.swkweSetArticles['grossAmount']}
{$detailPrice = $detailAmount / $details['quantity']}
{else}
{$detailPrice = (!$additional.show_net) ? $details.swkweSetArticles->getNetPrice() : $details.swkweSetArticles->getGrossPrice()}
{$detailAmount = (!$additional.show_net) ? $details.swkweSetArticles->getNetAmount() : $details.swkweSetArticles->getGrossAmount()}
{/if}
{else}
{$detailPrice = $details.price}
{$detailAmount = $details.amount}
{/if}

{{$position-$subPosition+1}|fill:4}  {$details.ordernumber|fill:20}  {$details.articlename|fill:49}  {$details.quantity|fill:6}  {$detailPrice|padding:8|currency|unescape:"htmlall"}  {$detailAmount|padding:8|currency|unescape:"htmlall"}
{if $details.swkweSetArticles}
{if is_array($details.swkweSetArticles)}
{foreach $details.swkweSetArticles['options'] as $option}
 - {if $option['quantity'] != 1}{$option['quantity']}x {/if}{$option['name']}
{if $option['subSetOrder']}
{foreach $option['subSetOrder']['options'] as $subSetOption}
   - {if {$subSetOption['quantity']} != 1}{$subSetOption['quantity']}x {/if}{$subSetOption['name']}
{/foreach}
{/if}
{/foreach}
{else}
{foreach $details.swkweSetArticles->getOptions() as $option}
 - {if $option->getQuantity() != 1}{$option->getQuantity()}x {/if}{$option->getName()}
{if $option->getSubSetOrder()}
{foreach $option->getSubSetOrder()->getOptions() as $subSetOption}
   - {if {$subSetOption->getQuantity()} != 1}{$subSetOption->getQuantity()}x {/if}{$subSetOption->getName()}
{/foreach}
{/if}
{/foreach}
{/if}
{/if}
{elseif in_array($details.modus, [20, 21])}
{$subPosition = $subPosition + 1}
{/if}
{/foreach}

HTML:
{$subPosition = 0}
{foreach item=details key=position from=$sOrderDetails}
    {if $details.swkweSetArticles || !in_array($details.modus, [20, 21])}
        <tr>
            <td style="border-bottom:1px solid #cccccc;">{$position-$subPosition+1|fill:4} </td>
            <td style="border-bottom:1px solid #cccccc;">{if $details.image.src.0 && in_array($details.modus, [0, 20])}<img style="height: 57px;" height="57" src="{$details.image.src.0}" alt="{$details.articlename}" />{else} {/if}</td>
            <td style="border-bottom:1px solid #cccccc;">
              {$details.articlename|wordwrap:80|indent:4}<br>
              Artikel-Nr: {$details.ordernumber|fill:20}
                {if $details.swkweSetArticles}
                    {if is_array($details.swkweSetArticles)}
                        {foreach $details.swkweSetArticles['options'] as $option}
                            <br>- {if $option['quantity'] != 1}{$option['quantity']}x {/if}{$option['name']}
                            {if $option['subSetOrder']}
                                {foreach $option['subSetOrder']['options'] as $subSetOption}
                                    <br>  - {if $subSetOption['quantity'] != 1}{$subSetOption['quantity']}x {/if}{$subSetOption['name']}
                                {/foreach}
                            {/if}
                        {/foreach}
                        {$detailAmount = (!$additional.show_net) ? $details.swkweSetArticles['netAmount'] : $details.swkweSetArticles['grossAmount']}
                        {$detailPrice = $detailAmount / $details['quantity']}
                    {else}
                        {foreach $details.swkweSetArticles->getOptions() as $option}
                            <br>- {if $option->getQuantity() != 1}{$option->getQuantity()}x {/if}{$option->getName()}
                            {if $option->getSubSetOrder()}
                                {foreach $option->getSubSetOrder()->getOptions() as $subSetOption}
                                    <br>  - {if $subSetOption->getQuantity() != 1}{$subSetOption->getQuantity()}x {/if}{$subSetOption->getName()}
                                {/foreach}
                            {/if}
                        {/foreach}
                        {$detailPrice = (!$additional.show_net) ? $details.swkweSetArticles->getNetPrice() : $details.swkweSetArticles->getGrossPrice()}
                        {$detailAmount = (!$additional.show_net) ? $details.swkweSetArticles->getNetAmount() : $details.swkweSetArticles->getGrossAmount()}
                    {/if}
                {else}
                    {$detailPrice = $details.price}
                    {$detailAmount = $details.amount}
                {/if}
            </td>
            <td style="border-bottom:1px solid #cccccc;">{$details.quantity|fill:6}</td>
            <td style="border-bottom:1px solid #cccccc;">{$detailPrice|padding:8|currency}</td>
            <td style="border-bottom:1px solid #cccccc;">{$detailAmount|padding:8|currency}</td>
        </tr>
    {elseif in_array($details.modus, [20, 21])}
        {$subPosition = $subPosition + 1}
    {/if}
{/foreach}