I found this article interesting, mainly because I agree with it, but mostly because it seems to contradict VMware documentation. Curious about your thoughts on this, from page 36 of the Fibre Channel SAN Configuration Guide:

When you use zoning, keep in mind the following items:
􀂄 ESX Server hosts that use shared storage for virtual machine failover or load
balancing must be in one zone.
􀂄 If you have a very large deployment, you might need to create separate zones for
different areas of functionality. For example, you can separate accounting from
human resources.
􀂄 It does not work well to create many small zones of, for example, two hosts with
four virtual machines each.