You can easily carry both in the bag. The covers and core design have enough difference in shape and strength where they can be a nice combo to work with. Having thrown a HyRoad in the past, I would consider it a benchmark ball. You can throw that in practice and it'll let you know to ball up to the Zen or you can go down as needed.
Most of the time on the fresh, I would start with the Zen and then transition to the HyRoad as things open up a bit.