An amp is an amp, if you are looking at breaker protection. If you want to use breakers on each of the outputs of the ZW, that are rated somewhat below the 15 amp main thermal breaker, there are many inexpensive but reliable options. First choice would be the Lionel #91 adjustable magnetic breaker.
I have used the Re-Cirk-It type breakers in various ratings for many years, here is a 2.5 amp type.