<?php
$arr1 = [
[1, 2, 3, 4],
[1, 2, 3, 4],
[1, 2, 3, 4],
];
$arr2 = [
[1, 2, 3, 4],
[1, 2, 3, 4],
];
$arr3 = [
[1, 2, 3, 4]
];
$arr = array_merge($arr1, $arr2, $arr3);
$res = [
array_sum(array_column($arr, 0)),
array_sum(array_column($arr, 1)),
array_sum(array_column($arr, 2)),
array_sum(array_column($arr, 3))
];
print_r($res);