MD3220 RAID

Hello,

I have an old MD3220 that I'm trying to repurpose AFTER I setup a new HA system running on it.  There are currently 3 disk groups - 8 drives RAID10/2 drive RAID1/ 4 drive RAID10.  The 1st 8 drive RAID group has free space on it.  The chassis has 9 slots available.  The thing is we have one node hooked up to it already and will be adding two more new servers to run vCenter 7 in HA mode and get rid of the old production server.

I have two options that I was thinking about - use the free space on DG1 for a new LUN, setup the new servers, create the new VMs and empty out the other disk groups, and expand the disk group and increase the RAID size *OR* put in 9 new drives, create 3 new drive groups (RAID10, RAID1, RAID1), create the new VMs, then empty out the old disk groups and add them to the new disk groups/arrays, expanding RAID10, and converting the two RAID1 disk groups to RAID10.

The questions are:  Can I add drives to a disk group?  Can I convert RAID 1 to RAID 10 on an MD3220?  Which way is the optimal method if I'm trying to keep  the old production server online, setup 2 new servers with vCenter, and recover the old space and add it to the new setup?

Thanks in advance!