Sizing the lun for VMware host

One of the blogger came up with size the lun and came up with formula
30 x (your average disk size) + 30Gb VM swap + 15% of (30 x your average disk size) = calculated LUN size.
He taken into account of disk queuing which I suppose is disk I/O but fail to consider about queue depth at SP and FC level. To me while determining lun sizes and how many VMDK you are going to place it all depends upon the math of queue depth and you can place as many as you can till you oversubscribe the queue depth. For determining lun size queue depth would be biggest factor and it can avoid any bottleneck as well as SCSI abort.