Look at the specs of the decoder and remember the max current is for motor, lights, and smoke units added together. Use leds for the lights (place dual lights in series like the ones on the FA fake motor) and use track power for the smoke to lesson the current draw of these items.
If you want to use those decoders to run smoke units over 1/2 amp add a relay.
Also, although all 8 outputs are rated at 1/2 amp each, it might not be able to run all at the same time at max current.
Did you look into the D408 decoder? They have lower motor current, but they have 2 outputs that can handle 1 amp each. They are cheaper, so maybe one per loco if you have smoke units that want to run 1 amp.