Adding Munchkin to GTM

At the end of our Marketo landing pages, we have a parameterized Munchkin init function:

<script type="text/javascript" src="//munchkin.marketo.net//munchkin.js"></script><script>Munchkin.init('123-xxx-456', {parameter1: 'foo', parameter2: 'bar'});
</script>

We use Google Tag Manager across our sites (including our Marketo landing pages), and we would like to include the Munchkin code snippet in it, ie:

<script type="text/javascript">
(function() {
  var didInit = false;
  function initMunchkin() {
    if(didInit === false) {
      didInit = true;
      Munchkin.init('123-xxx-456');
    }
  }
  var s = document.createElement('script');
  s.type = 'text/javascript';
  s.async = true;
  s.src = '//munchkin.marketo.net/munchkin.js';
  s.onreadystatechange = function() {
    if (this.readyState == 'complete' || this.readyState == 'loaded') {
      initMunchkin();
    }
  };
  s.onload = initMunchkin;
  document.getElementsByTagName('head')[0].appendChild(s);
})();
</script>

Would that override/break the parameterized Munchkin code that is already being included on our pages?

Thanks in advance!

Mary