I am one of those CRAZY NUTS who adopted a dog without meeting it first. Can you imagine?!
Joking aside... I was able to work with a rescue who I was more than comfortable with, who had the dogs in multiple dog foster home settings. After talking several times with the rescue people and foster home, they helped me to decide on which dog would be best suited for our pack.
We were originally looking for a very young male pup, and ended up with a 5 month old female.
Amazingly enough, she is the PERFECT addition to our family. I would never have imagined a dog could be so compatible with the dogs we already had!
Point is-- if you are working with a rescue who truely know their stuff, I wouldn't be worried. I'm sure you'll know when you find the right one.