Well... its official
clustering is not supported by fusion 9 studio.
A customer support representative got back to me after sending an email to blackmagic asking the same question. If there is someone else wondering, as far as August 2018, clustering is not supported in fusion 9 studio.
Hope this help any other soul searching for this.
I just can't get over my head why is still being referenced and even being featured in the product page of fusion 9 studio.
too bad, soooooooooo sad