You're actually getting two different kinds of rummynoses. It's pretty confusing because one source considers hemigrammus rhodostomus to be the "true" rummynose while another book considers hemigrammus bleheri to be the true rummynose. Either way, you're getting five of each and really, unless you know what to look for, you can't tell the difference. Just some very subtle differences in the red markings.
And yup, these guys definitely school together. They tried to school with my betta for a while. They'll just spend all day going back and forth in a big group, cruising the plants. I'm so happy that they're going to go to such a nice tank.