how to expand an initiator group to add new host

We have a VMAX 40k with a masking view for the single ESX host.  So, we have a masking view for it.  At the time of creation, I was told it would be single host.

MV_Host1: IG_Host1, SG_Host1, PG_Host1

Now, they want to add an ESX host to make it a cluster.  To avoid downtime, one way is to add the initiators of the new hosts to existing IG. 

I would like to create a new IG for the new host.  Create a new parent IG to include the children IG.  Then, creating a new masking view with a new SG to include all the luns in SG_Host1.  Then delete the masking view MV_Host1.  Is it possible to do it without downtime?

MV_Cluster:

IG_Parent (Children IG: IG_Host1, IG_Host2)

SG_Cluster (copy all the luns from SG_Host1)

PG_Host1