Как создать многомерный массив из двух обычных?

$personal_number= array(
"Вася" => "8864",
"Петя" => "3455",
"Саша" => "1221",
);

$scores = array(
"0" => "1",
"1" => "2",
"2" => "3",
"3" => "4",
"4" => "5",
"5" => "6",
"6" => "7",
"7" => "8",
"8" => "9",
"9" => "10",
 
);

$mixed = array (
 
"0" => 
            "0" => "8864 - 1",
            "1" => "8864 - 2",
            "2" => "8864 - 3",
            "3" => "8864 - 4",
"1" => 
            "0" => "8864 - 5",
            "1" => "8864 - 6",
            "2" => "8864 - 7",
            "3" => "8864 - 8",
"2" =>          
            "0" => "8864 - 9",
            "1" => "8864 - 10",
            "2" => "3455 - 1",
            "3" => "3455 - 2",
"3" => 
            "0" => "3455 - 3",
            "1" => "3455 - 4",
            "2" => "3455 - 5",
            "3" => "3455 - 6",
"4" => 
            "0" => "3455 - 7",
            "1" => "3455 - 8",
            "2" => "3455 - 9",
            "3" => "3455 - 10",
"5" => 
            "0" => "1221 - 1",
            "1" => "1221 - 2",
            "2" => "1221 - 3",
            "3" => "1221 - 4",
"6" => 
            "0" => "1221 - 5",
            "1" => "1221 - 6",
            "2" => "1221 - 7",
            "3" => "1221 - 8",
"7" =>          
            "0" => "1221 - 9",
            "1" => "1221 - 10",
);

$personal_number = array_values($personal_number);
$personal_number_c = count($personal_number);
$scores_c = count($scores);
 
$rrr='0';
$rr='0';
for($j = 0; $j < $personal_number_c; $j++) {
    for($jh = 0; $jh < $scores_c; $jh++) {
        if($rrr == '4'){$rrr='0';$rr++;}
        $mixed[$rr][$rrr] = $personal_number[$j].' - '.$scores[$jh];
        $rrr++;
    }
}

$scores = range(1, 10);
$personal_number = [
    'Вася' => 8864,
    'Петя' => 3455,
    'Саша' => 1221,
];
 
$tmp = [];
foreach ($personal_number as $number) {
    foreach ($scores as $score) {
        $tmp[] = "$number - $score";
    }
}
 
$result = array_chunk($tmp, 4);
var_dump($result);