Hi BB,
I have kept Cardinals & Neon’s together and they school fine.. The answer would really depend on the species of Tetras that you’re planning on keeping though!
Bleeding hearts & Congo Tetra would not school with Cardinal or Neon’s for instance, someone else may be able to answer for definite but I would think that species the same size and body shape should school i.e. Glow lights, Neon’s, Cardinal, Black neon, Embers etc...
Personally I would advise getting more of the same species rather than a mixture... To thrive they should really be kept in groups no less than six of each species (more is always preferable).