Bans seem fair to me.
It does seem that DOPS could do with a bit more clarity in their explanations, which are wordy but often fail to get across the thought process behind why individual bans are of certain lengths when compared to others (the below isn't based on anything, just using the numbers as an example).
For instance, in this case two players have been banned for fighting after the end of the game. Stofflet's ban is double that of the other chap involved, because he started it, and the other player was not not expecting the punch. This seems entirely fair, as he should get the 3 for being involved in the fight (just like the other guy did), 2 for starting it, and the extra one for striking an unsuspecting opponent.
You can then avoid contrast with Springer's ban by explaining that, which could be along the lines of 2 for striking an opponent who couldn't defend himself, two for striking an opponent after the end of the game (not sure you could call this instigating a fight) and an extra one for the second and third strikes.
This stops the arguments about 'but so and so got this many games' and also sets a precedent for any future instances, though obviously mitigating and aggravating factors to each individual case may alter things slightly.