Why not do those expressions but on heads you prefer? Like get an animated film you like and look at animationscreencaps.com
or lookup the character turnaround sheets for them and draw expressions matching all of the loomis ones.
The important part is noticing which parts of the head are moving to show the expressions. It's mostly the brow + eyes doing the work, with the mouth clarifying it. If you cover the mouth you can still tell what expression it is.
Never be limited by the particular style someone is teaching in, always try to understand the concepts they are teaching and see how you can apply it universally.