the only problems that i forsee are that the puppies will bond more with each other than with the humans. on one hand this is what you want because yes they will keep each other company. on the other hand i do know of 2 gsd who both have severe sep anxiety from each other. they cannot be separated even for a short while without problems. i am not trying to rain on your parade because your pups will likely do fine, but i did feel compelled to at least share my experience. something to think about that's all.