It may be far, I'm not keeping track on where their travels have taken them. I did find it curious that Daryl and Meryl seemed to know where they were in the woods a few episodes back, debating on the location of a river.
The advantage/hope of traveling that far is 1) Rick is intimately familiar with the town and 2) it's unlikely that the Gov's crew had already looted it.
Yeah I agree that most of the time it doesn't really matter -exactly- where the characters are. But clearly this show plays it fast and loose as far as having characters miraculously end up in specific places (such as Merle being "lucky" enough to end up in Woodbury in the first place after Atlanta or Tyreese's group conveniently finding their way to the prison and then to Woodbury). You yourself mentioned Daryl and Merle's improbable knowledge of the local woods. Basically characters just auto-magically seem to be in the right place at the right time a wee-bit too often.
Ultimately the show should follow its own established rules for how hard it is to travel in this post-ZA world. We saw how hard it was for Rick to make his way to Atlanta in the first few episodes. I just don't think it made much sense for the multi-hundred mile "return trip" back to Kentucky to be glossed over like it was just a routine few-hour day-trip. If Rick, Carl and Michonne were simply after getting more guns they could have broken into literally hundreds of police stations closer to the prison than Rick's home town was.
Like I said it was cool enough to see Morgan again for what it was worth. But in order to work him back into a new episode the show's creators had to hope we would forget that he was hundreds of miles away on the far side of Atlanta through countless Walker herds. Unfortunately I didn't forget.
