If I was to add a third to my pack which sex would be best or does it matter? Lab Ruby is a she, Husky Balon is a he?

I think since you have one of each, it really just depends on your current dogs. Since Mishka i've just gotten boys and it hasn't made much of a difference at all.

I would lean on saying that it depends on the dogs themselves, rather than just sex (assuming they are fixed).

We had a boy and a girl, then adopted Snow...the other two were very submissive, where snow is definitely the established Alpha now..so it really just depends on your current dogs, and the dog you are looking to adopt.

We have three dogs of which only one is a husky(F), the other is a Lab(M) and the last one added was a BeagleXGSD(F).

The BeagleXGSD was in pretty poor shape when we fostered her (and later adopted her) and in the end she became the alpha, essentially stealing the rank from Maya our Husky. As a result we had about 8 months of instability between the females as they placed themselves but in the end the Husky tolerates the Beagle's control of the pack because, frankly, she's a natural at it. She isn't overly aggressive and manages to be playful in her manipulation.

Once the rank is firmly in place we'll start to feed her first as a sign that we acknowledge her rank.

Well I wouldn't be getting another until Balon is older, but right now I believe Ruby is boss, but she isn't demanding so its hard to see if it will end up that way. Balon plays at humping her (I know its dominace lol) but she just usually looks around and shoots him a look, and sometimes growls and he backs right off. Ruby was spayed at 5 months Balon will be neutered soon as he can!