Two GTM's in HA pairs in 2 Datacenter

We have two LTM in HA pair in two of our Datacenters I want to run two GTM's in HA pairs on the same appliance

 

DC A A-GTM-01 (Active) A-GTM-02 (Standby) Floating IP

 

DC B B-GTM-01 (Active) B-GTM-02 (Standby) Floating IP

 

I am planning manually copy the certificate on both GTM,My question is do I have put gtm_add only GTM in HA pairs only on one datacenter and all the self ip address My second question is do I have run the gtm_add on ha-pair also or can just enable syncronisation.We would be using this GTM as Bind

 

Thanks!