Tlov - it was really hard when we got them 8 weeks ago...just to keep track of them and deal with housebreaking. It has gotten easier but we still have our issues. One loves to play and is more energetic so when Bella is done I have to sometimes drag Sage off of her and make her calm down so they don't fight. We don't have resource guarding issues, but Sage does everything very fast and Bella takes her time so when they are eating we make sure to be close by so Sage doesn't try to steal Bella's food and they now get their carrots in their crates because Bella takes her time to eat it and Sage would steal it right out of her mouth.
We do have to train and brush/clean ears separately because the one not being attended too just gets in the way. It's cool to see their personalities though. Bella is a affection motivated and is picking up commands very well where Sage is Prey/food motivated and she is more difficult to get focused sometimes.
So, short answer, it has it's challenges but I wouldn't give either of them up.