They are far too low-contrast for users who want to include them as footnotes, or call attention to something in a specific order using them. As demonstrated:
It's even worse if used as footnotes:
Don't cheat. Sit back two feet away from your display and tell me if you can discern them without knowing what order they are in.
My recomendation: Make them like the arrows. 
or if you can't be bothered to do that, use the twemoji numbers as they are much higher contrast in comparison.
Once updated, refer back to this post to see if they can be discerned from a distance away.