Hi madwhitehat, you took the words right out of my mouth!
Of course it can work introducing them later too, but much riskier, particularly when one of the animals is habituated to the enclosure, so by raising them from hatchlings/juveniles together in the same (tiny) space, more chance of success, I think.
You (Gregg) have a beautiful looking Bosc`s, whatever happens in the future!