I wouldn't use the term aggressive. They are almost blind. If they see a shadow of something passing, they will try to eat it in the hope that it is food. For example, I had two frogs which mistook my betta's long flowing tail as food and bit it. I don't call that aggression, I call it instinctive behaviour.
As for small tetras and endlers, I don't think they'd take down a fit healthy adult. Maybe a sick one, or possibly during the night if a small fish 'slept' on the bottom of the tank. But they would eat fry, if they caught them.
I would be more concerned with adfs starving to death in a tank with endlers and small tetras. My experience with endlers is that they'd eat all the fish food, then all the frog food before the frogs had chance to find it. Because they are almost blind, adfs rely on their sense of smell to find food, and that takes time. My endlers would not leave any food lying round long enough for a frog to find it.
Like fish, adfs should be fed bloodworm only as a treat. they need a commercailly produced food as their staple diet; food like HBH frog and tadpole food in the US and Zoo Med frog and tadpole food in the UK. But just because the pack says frog food doesn't mean fish won't eat it.
This is for african dwarf frogs, which don't grow very big. African clawed frogs grow a lot bigger and will eat endlers and tetras. If you decide to get frogs, make sure you know how to tell the difference.