That would be a good idea, unless Arya has killed Littlefinger already.

@RustyShackleworth said:

If the Hound makes it to Winterfell and meets Arya again he may be have information for her (as well as for Sansa and Jon) about Littlefinger and the things he did that led to Ned Stark's capture and death.

What do you guys think? I doubt the Hound has any affection for Littlefinger.

Bran already knows what happened. He saw it all. Littlefinger is as good as done.

Arya may trust the Hound more that she trusts Bran

I think that things are setting up for Sansa to kill Little finger because Arya hinted that Sansa should use a mask and gave her the knife.