<?php

$nomes = ["João", "Pedro", "Matheus"];
$contagem = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15];

$a = [];

foreach($nomes as $nome) {
    $arrTemp = array_fill(0, count($contagem), $nome);
    $a = array_merge($a, $arrTemp);
}

echo "Total: " . count($a);
echo PHP_EOL;
var_dump($a);