Yes, they are
So, they should be like
\firstcommand { s m m m }
{
<first command code>
}
\secondcommand { s m m m }
{
<second command code>
}
\NewDocumentCommand \parentcommand { s m m m )
{
\firstcommand { #1 #2 #3 #4 }
\secondcommand { #1 #2 #3 #4 }
}