Out of (birth) order adoptions

I am looking for information from families who have successfully adopted out of birth order. As an adult adoptee, I personally think that "birth" order is somewhat ridiculous. I was biologically the oldest, but adopted and raised as the youngest. However, I acted mostly like an oldest while my older brother (also adopted) acted, oh, much less like an oldest. That being said, we have two children adopted from Colombia ages (almost) 3 and 1 1/2. Neither are the oldest or youngest biologically, that just happens to be where they are now after we adopted them. We are beginning the process of adopting a sibling group of 2 or 3 children up to age 10 from Colombia. Now, I understand all the risks associated with bringing older children who have had traumatic early years into a home with younger children. What I am looking for is someone who has done it successfully and what they found that worked best. I would love any advice for how to make the transition smooth and how to handle meltdowns (by any of the children) in response to the adoption. Basically, I'd love any advice on how to make this next adoption a successful one. I'm also posting this in another section in order to get as much response as possible. Thank you! Megan