Host "alternative future" conversations. Invite anyone in the organization to attend; provide no agenda other than to imagine the ideal, transformed organization 5 years from now. The more boundary spanning leaders it has, the stronger it will be.
Invite leaders from other units to your team meetings so they can discuss how each unit can help the other to solve pressing organizational problems.
Turf battles, the intransigence of silos, navigating the organizational matrix, front and back office barriers — in other words, working across barriers of function and expertise rather than above or below them — were the issues keeping them up at night most.