Can you control 2 mth starter sets independently (each with its own loop of track) on the same layout by using different starter set commander remotes?

Can two MTH starter sets be run on the same layout or would they conflict with each other? I'm thlnking about running 2 starter sets on the same layout, each with its own set of tracks, z-500 power supply and controlled by the commander remote which came packaged with each set. Is that possible? Do mth starter set engines each have their own unique code or when you press the remote contol which came with one starter set, would that command you send be acted on by the other set's engine too? To keep costs down, I don't mind using the two remotes for each engine if I can. In other words - does a starter set remote activate the engines in all starter sets, or is each remote programmed to only work with the engine that was in the set it came with? If that's the case, can a starter remote and engine be reprogrammed to only work as a pair with each other and not interfere with other starter set locomotives?