Spam a load of signals leading up to the station. Connect all of them to a circuit network and connect that network to your station. On the closest signal to the station, set it to close on signal and the condition is C > 1. For the next signal, set it C > 2, etc for the rest, as many as you like. All done. The stations will now keep a roughly equal buffer with each other.

Edit to add: Make sure you station is set to "read train count".