With living animals you can never be sure of anything. I had a two week old chick kill a sibling out of the blue. They were hatched together and were being raised together. Same age, no integration, and no idea what triggered it. So I can't guarantee you that everything will go great. But I'd try it and expect things to go well. They often do. Just observe.
That close together in age I'd just put them together when I could observe. You could house them side by side for a few days first but it's probably not necessary. That would be my fallback position if it doesn't work out. at first.