Since I have several LUNs I will do the same in all datastores in both hosts. Similar to this:
After disabling the paths I will shutdown all VMs, put the farm in maintenance mode, and then disconnect the SAS cable for the disabled path (old storage, controller B) and connect it to the new storage (controller A).
For some time I will run without storage path redundancy.
I will attach all new datastores, migrate the VMS, unmount old datastores and later connect the second SAS cable to the new storage (controller B).
Your plan is good. Keep in mind that issues with multipathing can bring hostd down. I would recommend at least a storage rescan and if possible a reboot of each host when the storage migration is completed.