That actually looks like a pretty good mix, especially with the added worm castings. I didn't see any mention of lime in their mix. I would contact them to find out for sure. If not, I'd test it's pH when you get it and add some dolomite lime if needed. With the worm castings you won't need to use as many nutes. I would also add some mychorrhizal fungi to it. They will feed on the organic matter and help break it down and be more easily absorbed by the roots.