Hi
you should know that there are two types of pools virtual and linear
if you create a virtual pool you can add more virtual disk groups to it but they should be of the same raid level you can not add disks to a virtual disk group. if you create a linear pool and you have one linear disk group in it you are limited to 16 disks in a group but you can add disks up to that limit.
read this manual
HPE MSA 1040/2040 SMU Reference Guide
also a pool is active on one controller and best practice is to create on virtual disk per pool
HP MSA 1040/2040 Best Practices
Regards