I'm guessing the dogs would also be able to sniff out ores, and you could probably (In complete Fallout 3 fashion) tell them to go get you food or other small items either from your house or from the wilderness. This could be exceptionally useful, IMO. And I'm guessing you would need to attach some kind of item to the dogs to make them no longer be wild, (similar to the pig saddle, but with an actual use).
So it wouldnt be reqiuired to have a dog companion.
Then again, I am a major fan of Fable and Fallout, so dog companions make me happy no matter their defects.