You can use the ZW to power your trains with no problems. There is no limit to the power output of each throttle. You can get the full available power from the ZW at one throttle if you want. Just because the ZW has 4 throttles does not mean each throttle has only 1/4 of the output- that is a common misconception. You can draw any combination of power from any combination of throttles until you reach the transformer's power limit. You will be hard pressed to overload a ZW unless you have 4 trains running and many accessories and lights.

Larry