Any install of an Abbey Road Orchestra product from the Spitfire App will create a folder called "Spitfire Audio - Abbey Road Orchestra" in your desired install location.
Each time you install an Abbey Road Orchestra library, you must install to this folder for the install to merge correctly.
In the Spitfire Audio App, having clicked "install" below a product, you can choose the desired location using the folder Icon on the right hand side:
For first time installs, install to your desired location for this folder to be created. Once installed, you will see the following: