CakePHP 2.10 Routing one unique slug multiple models

Question

I have been attempting to modify a clients website by allowing /slug to access both the pages and users models/controllers. I have read all of CakePHP 2 Routing book, however it does not go into detail about how to accomplish such a thing. I have tried this:

app/config/routes.php

App::uses('SlugRoute', 'Lib/Routing/Route');
Router::connect('/:slug', ['controller' => 'pages', 'action' => 'display'], ['routeClass' => 'SlugRoute', 'model' => 'Page']);
Router::connect('/:username', ['controller' => 'users', 'action' => 'view'], ['routeClass' => 'SlugRoute', 'model' => 'User']);

app/Lib/Routing/Route/SlugRoute.php

App::uses('Page', 'Model');
App::uses('User', 'Model');
App::uses('CakeRoute', 'Routing/Route');
App::uses('ClassRegistry', 'Utility');

class SlugRoute extends CakeRoute {

  public function parse($url) {
      $params = parent::parse($url);
      if (empty($params)) {
          return false;
      }
          
      $model = $this->options['model'];
      
      $this->{$model} = ClassRegistry::init($model); 
      $result = $this->{$model}->find('first', [
          'conditions' => [
              $model.'.slug' => $params['slug'],
          ],
          'fields' => array($model.'.id'),
          'recursive' => -1,
      ]);

      if ($result) {
          $params['pass'] = array($result[$model]['id']);
          print_r($params);
          return $params;
      }
      
      return false;
  }
}

Sadly this works for the pages, but does not work for users. I've considered modifying the params being returned and setting the controller/model, view, etc. But I do not believe this to be the proper way to do this. Any advice or solutions?