I never really saw a point for Sawk and Throh to evolve. I mean, personally, I'd love to see an evolution for them, but...what would they look like, and would they basically be hitmon clones all over again? What would separate them from the hitmons? So many questions, and yet so little answers, which is why I kind of feel it's best to leave them as it is. Audino is also another one that just isn't fit for an evo. What else can it do? It could possibly grow more powerful offensively of course, but there are so many other more preferable normal types that outclass Audino entirely.
It's kind of a sad thing, because these Pokemon would definitely be interesting with an evolution at any rate, but the problem being is that there are more preferable Pokemon to choose from, at least competitively. That, and there's really no point to evolving them.