Hmmm...
We need some rules about Widget takeover -- aka clobbering -- aka knocking out
Let's keep the terminology active Navigator -- means the Navigator currently taking over a Zone.
Rule: Navigators can't overlap.
If Navigator1 has any Widgets in common with Navigator2, activating one automatically deactivates the other.
However, let's assume a control surface divided into A and B Zones.
If Navigator1 (ZoneA) has no Widgets in common with Navigator2 (ZoneB), they can activate/deactivate independently with no issues.