Excessive angulation, even on short legged dogs, can look very flash and give you a wide expansive gait but such angulation is far less stable than the correct moderate angulation. A dog which is required to pull needs very firm joints. Sled dogs require good clearance to get through the snow. Short legged dogs will experience more difficulty and expend more energy trying to move through heavy snow. The Siberian standard calls for a moderately angled pelvis, with the set on of the tail just below the level of the topline.
Common faults are flat croups and high set tails.
Flat croups will have an effect on drive and reach-through from behind. A steeply angled croup will restrict drive. However, they should not be expected to carry the tail high up at all times - so long as it shows lift in movement. It is common for a dog settled into its stride to trail the tail straight out behind. It is also correct for the tail to hang relaxed while the dog is in stance.