The short answer is that you should break your software array, or rebuild your server with a RAID controller instead of using software RAID.
WHS itself doesn't support RAID. It's certainly possible to install on a RAID controller (my first server was built with a hardware-accelerated RAID controller), and many people have had success that way, but it's still unsupported. However, software RAID is managed by the operating system. Since the disks appear individually in the Disk Management MMC snap-in, they will appear as separate disks in the console. You are unlikely to find a way around this.
I'm not on the WHS team, I just post a lot. :)