Use Document Order

Rule: Always start by using document order.
Unless you need to re-order elements, use the document order.
When expressions evaluate, they are return in document order:
```
<xsl:apply-templates select="A|B"/>
```
at this context:
```
<A/><C/><B/><C/><C/><A/>
```
returns:
```
<A/><B/><A/>
```