Hello @ares ,
I understand that you would like to configure multi-region load balancing with Traffic Manager, load balancers and 3rd party firewalls.
You can refer the below architectures which shows Traffic manager with load balancer setup:
You can then refer the below document which shows the design for using Azure load balancers with 3rd party NVAs:
Kindly let us know if the above helps or you need further assistance on this issue.
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