The thing is, all those fish are going to occupy the same place in the tank, middle-upper.
Why not choose 12 tetra. 6 of 2 of the species you mention, some bottom dwellers like sterbai corys (if having a sand or extra smooth gravel) and a centre piece like a pearl gourami.
I will say something against rosy tetra, they can bully and can become quite territorial and dont school together anything like the way neons will. They are beautiful fish though.
Also some real beautys are harliquin rasbora, these stick close together.
Fish die belly upward and rise to the surface. It's their way of falling.