They will do just fine in it if you want to use it. I have some tiny dwarfs growing in the gritty mix that I use as companion plants to bonsai, but I would just use something like the 5:1:1 bark mix. The reason I say that is because by the time the soil has broken down, it's time to divide & repot. ;o) No sense in using the more expensive mix when the cheap one serves equally well.

Al