I've personally kept 1 barking tree frogs and 2 red eyed together without issues and they will still going strong when I sold them on two years later but only these three frogs were in a 40 gallon and I wouldn't have added more. Greens I'm not sure about with red eyes. If you kept the ambient in the mid 70s F and no lower than 20C at night. Just give the red eyes a small local area at 30C, this might work. They frogs need quarantined, fecals done and treated if neccessary before mixing and if it doesn't work then you would have to know when and be able to seperate them. I wouldn't mix with the fire bellies, they need UVB and it won't reach the floor to them without being harmful at the upper levels to the tree frogs. They also benefit from a basking spot and have toxins. For the well being of the other frogs and the fire bellies, it would be best to keep these in their own tank and a small 10-gallon will do fine.