Expression of a feedback circuit

I'm modelling a feedback circuit in Ltspice, however, I want to work out the transfer function for it. See below for the circuit.

Now I want the form of Vfb/VOA_o as:

So, I've thought about breaking up the circuit into two constituents to solve for this, as follows.

Would you say that this is the best way to approach this? What is the transfer function, if this is not the correct approach?