Teams may come down as a ho-stack and in general, downfield players should defend the biggest threat while trying to stay close to their assigned zone.
When teams realize it's a zone, they will likely spread out to occupy positions that our downfield defenders are assigned to.
The short deep and wings should generally stay tight and in front of the the most threatening offensive player that allows the defenders to maintain their relative position to each other. The deep deep is there for insurance against hucks.
Communication is key. players crossing over between zones need to be handed off using verbal and physical communication (pointing/shouting, "you have this guy", "I'm taking this")
Don't follow players into the handler space, simply let them go and find a new player to pick up-it may not happen immediately and you can anticipate which players can be handed off to you.