If you already have VXLAN enabled, you can split the 4 new hosts out to a new cluster ... verify VXLAN works, then add the additional resource pool to the provider. that's done for the elastic part.
when in elastic mode you'll have a 'primary' and multiple 'secondary' pools. from a programming perspective, it doesn't change ... since you target an Org vDC (not the pools/clusters which back them).