3fsh
Fish Addict
If they aren't the same size, that could explain why they aren't schooling together. The 2in ones are a lot faster and the smaller ones tend to get left in the dust. The same applies to the longfinned variety vs. the short finned variety. The ones with longer fins aren't as fast and therefore do not school with the shorter finned danios. This is just my experience.
I have 5 or so short finned striped danios in a 12g right now and they school really well and leave all of the other fish alone.