Storage Space: Parity disk usage

I want to create a parity space that maximizes the disk utilization. My six disks are 2x3TB, 2x2TB, and 2x1TB.   (Using TB here for simplicity. I aware of the space calculation for TiB.)

If I create it with 6 columns, I would have only 5TB usable since the 1TB disks limit the usable space:
Column 1: 3TB Disk
Column 2: 3TB Disk
Column 3: 2TB Disk
Column 4: 2TB Disk
Column 5: 1TB Disk
Column 6: 1TB Disk
...so 6*1TB - 1TB = 5TB


If I create it with 4 columns, would I have 9TB usable?
Column 1: 3TB Disk
Column 2: 3TB Disk
Column 3: 2TB+1TB Disks
Column 4: 2TB+1TB Disks
...so 4*3TB - 3TB = 9TB