My use case is kind of the reverse of the current licensing model. I want to have a Mac mini at home with no USB devices connected. Occasionally, when I am out I want to connect an iPhone to either my Surface Pro or Android tablet or another PC, use Xcode on the Mac mini through remote screen sharing (VNC or whatever) and deploy on my iPhone which I have with me. It would make more sense to pay for the Mac Mini license which is the client according to your model but in my case that is really the server.
It would not make sense for me to buy separate licenses for my Surface Pro/Android tablet/remote PC as I would not be using either of them in a constant basis.