Central management tools provide detailed, hands on management of devices and policies via a GUI. Orchestration provides automated configuration and deployment of those same devices via a programmatic interface - APIs.
So the question is, what system has management authority? If a vendor's central management tool makes configuration changes, will those changes flow into the SDN controller? What if they are counter to policies set via the controller?
It seems there is room for confusion if not disaster if you try to deploy both an orchestration system and a central management system. But I have yet to see a means to do basic device management in SDN controllers - back up and restore images and configs, cert management, license management.