What you need to watch out for is contention or fighting between thermostats. In a large zone with multiple units I have seen one unit heating and one unit cooling. Obviously this is not the most energy efficient way of conditioning the space.
If you are fortunate enough to have a DDC system with some horsepower, you could write a quick and dirty routine to prevent a new mode from being entered unless all units were in vent only mode.
Lacking a DDC system if your units use sensors instead of contact closure stats, you could wire the stats in a series parallel configuration. This would have all units see the average temperature of the space.
If you have thermostats you could use relays to prevent zone contention.