PHP update multidimensional array values from same path multidmensional array

I need to update a multidimensional array by same key paths of a multidimensional array.

I think my code can be better condensed :

//source
$array = [
  "hero" => [
    "name" => "Peter",
    "job" => "Spider Man"
  ],
  "dog" => [
    "age" => 5,
    "toys" => [
      "first" => "bone",
      "second" => "ball"
    ]
  ]
];

//values to update
$toUpdate = [
  "hero" => [
    "name" => "Peter Parker",
    "age" => 26
  ],
  "dog" => [
    "name" => "Rex",
    "toys" => [
      "second" => "frisbee"
    ]
  ]
];

$paths = nested_values($toUpdate);

foreach ($paths as $path => $value) {
  $arr = &$array;
  $parts = explode('/', $path);
  foreach($parts as $key){
    $arr = &$arr[$key];
  }
  $arr = $value;
}

function nested_values ($array, $path="") {
  $output = array();
  foreach ($array as $key => $value) {
    if (is_array($value)) {
      $output = array_merge($output, nested_values($value, (!empty($path)) ? $path.$key."/" : $key."/"));
    }
    else $output[$path.$key] = $value;
  }
  return $output;
}

var_dump($array);

/*
(array) [2 elements]
  hero: 
    (array) [3 elements]
      name: (string) "Peter Parker"
      job: (string) "Spider Man"
      age: (integer) 26 
  dog: 
    (array) [3 elements]
      age: (integer) 5 
      toys: 
        (array) [2 elements]
          first: (string) "bone"
          second: (string) "frisbee"
      name: (string) "Rex"
*/