It's a common theme when coming from more traditional architectures especially big iron like HDS/VMax where getting the most out of the array required many many small volumes. Hence the need to support many thousands of volumes and huge consistency groups on those architectures.
3PAR wasn't built in that era or in that way and so doesn't require the same level of micro management around LDevs etc. Structuring the storage in that manner in many ways actively works against 3PARs architectural advantages, yes it'll work but you're going to be making a rod for your own back longer term.
You can still keep multiple volumes If you need to ensure very high queue depths etc but you could drastically reduce the numbers to simplify things whilst still maintaining performance. I'd take a look at the 3PAR architecture and concepts guide which should highlight a few of the fairly significant differences.
Why buy into 3PAR and treat it like a HDS/EMC box ?