You can also have a hidden fiddle yard with trains loaded and ready to go. Look at the driver commands to set and clear session variables. Your driver can set a variable that another train is waiting for. Can't recall the setup. Look at one of my sessions for the Port Loleta route from Philskene.
There are also driver commands to load an entire consist. You don't even have to preload the staged trains.
There are also driver commands to load an entire consist. You don't even have to preload the staged trains.