I feel like Chernarus and Livonia sharing a hive works fine and they are free maps now for all too.
I think Nasdara and Sakhal shd have their own hives each if possible. Caveat being that is harder to know for sure until we've played it. The two new maps are meant to have unique survival challenges (cold and getting started from spawn on Sakhal, heat and water etc on Nasdara). If you can play Sakhal official for half an hour, get a water container, fill up at a spring and get an easy swap to Nasdara it negates the point of the survival challenge the map is meant to have.
IMO if you're going for more of a challenge, single hive for the one map only.