I saw that tank on the Nano Reef forum. Sure it's colorful, but I am not a fan of it simply because IMO, there is no room at all for growth. Of course it you frag enough, I guess it'll be fine.
I thought softies send out chemicals that fight off other softies. So I find it interesting to have so many softies so close to each other - and all seems to be thriving.
Enough water changes, protein skimming, and use of carbon may help curb any allopathic warfare.
Then again that is a lot of sofites in a small tank ...