Demonstrating how to concatenate arrays and then shuffle them (AngularJS).

gistfile1.js

// This is inside your callbacks, when you have gotten data -- somehow. Replace vars with the correct var names obviously.

$scope.combined = $scope.combined.concat(data);
$scope.combined = shuffle($scope.combined);

// Elsewhere...

function shuffle(array) {
  var currentIndex = array.length
    ,temporaryValue
    ,randomIndex;

  // While there remain elements to shuffle...
  while (0 !== currentIndex) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // And swap it with the current element.
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}

Very helpful, thank you! :)