multi-species

Hi! I'm trying to figure out if I can safely do a multi-species frog tank in a 56 gallon tank (30" x 18" x 24"). I'd like some dart frogs (maybe 4) and some tree frogs (4?). I'm wondering if I can possibly do two species of tree frogs. So far I'm leaning toward phyllobates for dart frogs...

I know that Cuban tree frogs will eat just about anything that can fit into their mouths, but what about a fully aquatic frog like the African dwarf? If a Cuban Tree frog was kept in an environment that includes these little dwarf frogs would they eventually become lunch? I'm sure the dwarfs can...