Got em

I'm now the proud carer of two young White's tree frogs, about an inch long each. I would have gotten 4, but there were only the two left! There's a breeder nearby that has some coming up for sale soon, but would it be safe to mix them, even after a quarantine period?
I'll post pictures of my little guys once they're in the big tank. For now they're in a smaller container where I can better monitor their feeding (and what little piggies they are!) So far they've had 10 small crickets and 30ish house flies between them in 2 days, but spat out the earthworms I offered. The axolotls don't like these new worms either though, so I assume they have a bad taste. I don't want to overfeed them, but they just seem SO HUNGRY! Should I just keep offering? I've read that these frogs are prone to obesity- true?