VMware (ESX 5.5) and SAN question about datastores

I think I have asked this question before, but I wanted to revisit and get some more clarity.

If I have three or four ESX hosts all connected to the same shared storage of 24TB, what is the best way to chop up the storage?

Should I make one large datastore of 24TB and attach it to all hosts, or even two smaller 10TB datastores or should I chop it up into smaller LUNS, like 2TB?

Here's what I'm seeing.  We are hosting about 600 virtual machines in a farm, spread across about 10 servers.  What I see when I log into vCenter is that the storage was chopped into several 2TB datastores and a few VMs are stored on datastore1 and a few VMs are stored on datastor2 and a few VMs stored on datastore3, etc.

So, now, I have ten 2TB datastores, each hosting about 60 VMs on each one.

My individual VMs are growing and I'm needing to expand some, but I'm limited because the space on each individual store is not enough to expand all of the machines on that store so I'm having to juggle.

Cumulatively, the total free space on the SAN is enough, but since it's all spread out all over the place, I can't utilize it.

My question to the client was "Who chopped up your SAN like that and why?"  

I would have made it one large store @ 24TB or maybe 2 @ 12TB and then put all of my VMs out there and expand them as I needed.  The way it is now, with it all chopped up, I'm having to look at sizes of VMs, free space on stores and move things around manually.  

So, the question is:  Do you chop up your array or delve it out as one big bucket of storage?

Thanks

Cliff