Like Davy said, what size tank are you keeping your current animals in?
Mini Bala Shark? I think all Bala Sharks get to be a little over a foot in length. If they tried selling a young Bala Shark to you as a "Mini" Bala Shark, then they lied...Heh.
The ADFs are better than ACFs(African Clawed Frogs) because they are much smaller, hence the name. They usually don't get any bigger than 2-3 inches. The only thing about frogs is that they well eat whatever fits in their mouth. Small fish, smaller frogs, you name it. If the tetras are larger varieties, say Black Skirts, or Buenoes Aires Tetras, then you have no need to worry. Chances are, the frog will stay near the bottom and mind its own business.
The Bala Shark, I don't know about. I've heard mixed opinions about them. You could probably keep it with the frog now, since it's still young. But I don't know if that will change if it gets older or not.