How can I interface the mechanical with the rotational domain in Simulink?

Hello,

in my Simulink/Simscape model I want to itnerface the mechnical (Simscape Multibody) with the rotational (Simscape Mechanical) domain. There are mutilpe ways to do this, and I have already found this demo. Here ist what it looks like in my model (which is part of the great wind trubine model):

The "Rotational Simscape Intf" block contains an ideal angular velocity source and a torque sensor to provide the shown outputs. Port G is then connected to a drive train including a gearbox and a generator. The problem I am now facing is that this setup is unrealistic and it does not take the torque and inertias of the drivetrain into account,as the ideal velocity source is defined to maintain the specified velocity. In other words, this interface only works one way: "Multibody" => "Mechanical (rotational)". How can I make this interface physically more valid, i.e. also taking effects of port G into account?

I am looking forward to an answer!