Well it seems that your input data is already given in a way that would make sorting useless. Try it this way:
// Grab the Tasks
$arraytask = $_POST["task"];
// Grab the Relusers
$arrayreluser = $_POST["reluser"];
// Grab the Usernames
$arrayuser = $_POST["user"];
// Grab the License Types
$arraylicense = $_POST["license"];
$result = array();
foreach($arraytask as $key => $val) {
$result[] = array(
'key' => $key,
'task' => $arraytask[$key],
'reluser' => $arrayreluser[$key],
'user' => $arrayuser[$key],
'license' => $arraylicense[$key],
'value' => implode(', ', array(
$arraytask[$key],
$arrayreluser[$key],
$arrayuser[$key],
$arraylicense[$key],
))
);
}
Now you have your "seemingly graceful" output, plus access to all the fields which you might need for working with your data. No need for sorting.