Is it possible to call directly from a model method from another model of the same component?
Is there any default Joomla option to call in such a way.
According to the my knowledge NO. Otherwise it will break the MVC architecture.
What you can do is
My Advice is to you is even if you figure out a way to do it, Don't do it. It will mess up your whole architecture.
If you have any issues please ask.
Yes You can
It will not break MVC architecture,
You can check like this
if(!class_exists('VirtueMartModelUser')) require(JPATH_VM_ADMINISTRATOR.DS.'models'.DS.'user.php');
$usermodel = VmModel::getModel('user');
$currentVMuser = $usermodel->getUser();
First you should include the model file in the required model then create the object. then call like above. This example is Virtue-mart using method