For a large organization that has more than 8 VMware Hosts (nodes) one should only make 8 node clusters for the time being according to the vSphere 4 Config Max doc.
If you look on page 7 it says "Configurations exceeding 40 VMs per host are limited to cluster size no greater than 8 nodes".
What that means is to be supported you have the following chart:
8 Nodes x 100 VMs / Node == 800 VMs per cluster max
9 Nodes x 40 VMs / Node == 360 VMs per cluster max
20 Nodes x 40 VMs/ Node == 800 VMs per cluster max
32 Nodes x 40 VMs / Node == 1,280 VMs per clustre max
Now I might not be too smart here some days though I think the math is pretty obvious. Either I do 4 clusters of 8 nodes to give me 3,200 VMs on 32 boxes or I stick them all into one nice big cluster and get 1,280 VMs out of those 32 boxes. Easy math to me.
The question I have out of this is, why do you document it this way? That sure is confusing and I could have easily missed that.