
Hello Pip, this is a failry tricky topic, but generally, if you are getting the pups as pets, it is usually best not to consider 2 pups together, of the same age, regardless if they are siblings or from different litters of similar age. The onlly way we let 2 pups go together is to experienced show homes, with other dogs in residence, usually while we wait to see which will the the better of the pair. We do often run on 2 pups together ourselves (or even 3!) but we ar full time with the dogs, with staff who work for us to fill in any gaps when we are not at home base, who can carry on the socialisation and oversee and interupt any developing problems.
The usual problems with 2 pups together are 1) Bond to each other, rather than to you. 2) Much harder to house train, how do you cach 2 piddling pups at the same time to direct to the newspaper/back door? 3)Much harder for general training, they egg each other on to naughtiness, and each gets only 50% of you attention. 4)Double the potential for destruction and disruption, one finds it the other rips it up! 5) Potentail for fighting, as they try to establish top dog status.
A better scenario, if you have your heart set on 2, is to leave a gap between them, get the training situation finished with the first pup, and past the chewing, naughty stage, then consider bringing another into the home. You can then give each you undivided training attention, and the 'top dog' thing should resolve itsefl naturally, without any arguments.
Gwen