Sorry I have to step back in, couldn't resist.

I moved mine from 10 to 20 after they kept bashing into the glass and kept falling to the floor. Snout abrasions are known in tree frogs and one reason is most likely because the enclosure isn't big enough for them to jump but I changed tank before this would likely happen.

They don't and most smaller sized tree frog are kept in 20-gals, where as larger tree frogs in at least 29-gals When it come to the size though you can put more smaller sized frogs in a tank of the same size than you could with larger ones, simple.

I wouldn't keep any frog in a 10-gal long term, not even a horned frog. They're good for raising froglets but for adults they're very small and limiting.

You can keep a human alive in a prison for a life but does it give the person a good life? Probably not but rightfully so.

Do what you want at the end of the day but you can't expect someone to recommend a tank size in which they don't agree on. It's a forum at the end of the day and everyone's going to give their opinions and advice, it's up to the reader to take the advice or not.