I keep Green tree frogs, 2 males who are now 5 years old. I would not dream of getting a female after seeing how many tadpoles you get from one female and one male. I gave you a base number of 200 because it's hard to find specifically how many tadpoles you can produce from one female on average as it depends on how good you are at caring for them. Now can you imagine trying to look after 200 frogs roughly the size of a large postage stamp? Now imagine how many frogs you could possibly get from 4 females?
Green Tree frogs are hard to sell and rehome. You will be left with many frogs you probably cannot care for, and so you might have to dispose of them. I know I wouldn't want to dispose of excess stock, but it's a possibility with that many frogs to look after. You cannot release them into the wild either.
You should reconsider this, and take all the advice we have given you. I really don't want to see another thread in 3 months when you are not sure what to do with all of your frogs.