Look - I love 90's id Software artwork as much as anyone else - but the WolfSS dogs are not very high quality. They're very flat and unshaded, consistent with the lack of detail with a lot of Wolfenstein. That's not to say they or Wolfenstein are bad, it's just that I really think these dogs are higher quality because they have more detail in them. That, and their more permissive license for usage, make a pretty easy case why I thought that the WolfSS dogs needed to be replaced.
These replacements definitely are more "Doomy"-feeling, in my opinion, with the really low resolution pixels combined with the shading that's present makes it a lot more consistent with the rest of Doom's art, even if the dogs themselves are pretty out of place in the first place with the game. In fact, the only thing I really would change is to render them from a more overhead perspective since the dogs aren't supposed to be exactly eye-level with the player.