Cake PHP 2 saveAssociated on two models with new model name

Question

I'm working inside a Cake PHP 2 project and need to save data from a model called Application into an identical model (just with a different name) called ApplicationVersionFive.

Application is saved using saveAssociated which takes the request data and saves it, I'm trying to simply call a $this->ApplicationVersionFive->saveAssociated() straight after where my regular Application is saved but nothing is saving to the database.

Here's my Application model:

<?php
App::uses('HttpSocket', 'Network/Http', 'HttpResponse');

class Application extends AppModel
{
    public $name = 'Application';

    public $hasMany = array('Redirect','ApplicationPromotion', 'ApplicationApiLink');

    public $hasOne = array('ApplicationResponse','ApplicationPayday','ApplicationInstallment','ApplicationSecured','ApplicationDebtmgmt','ApplicationReclaim', 'ApplicationPaydayIcicleHash');

        /*
        ** Perform something after a model save
        ** https://book.cakephp.org/2/en/models/callback-methods.html#aftersave
        */
        public function afterSave($created, $options) {
          
        }
}

And here's my ApplicationVersionFive:

<?php
App::uses('HttpSocket', 'Network/Http', 'HttpResponse');

class ApplicationVersionFive extends AppModel
{
    public $name = 'ApplicationVersionFive';

    public $hasMany = array('RedirectVersionFive','ApplicationPromotionVersionFive', 'ApplicationApiLinkVersionFive');

    public $hasOne = array('ApplicationResponseVersionFive','ApplicationPaydayVersionFive','ApplicationInstallmentVersionFive','ApplicationSecuredVersionFive','ApplicationDebtmgmtVersionFive','ApplicationReclaimVersionFive', 'ApplicationPaydayIcicleHashVersionFive');
}

Then I'm attempting to save in my controller:

// finally, save to db
// TODO: save to Version 5 model
$r = $this->Application->saveAssociated($this->request->data, array('deep' => true, 'settings' => $this->_settings));

$this->ApplicationVersionFive->saveAssociated($this->request->data, array('deep' => true, 'settings' => $this->_settings));

Unfortunately I cannot attach my whole controller, it's thousands of lines long, just a legacy business thing, what could I change to save to this separate model, effectively duplicating the data just under a different model name.