Since we need a CF'er (or back up CF'er) and a 2Bman, I think Hernandez on a 2-3 year deal is a great fit for us.
If Downs moves up quicker than expected, he still can have a key role on the team. If we fill an OF slot somehow, he can still have a key role.
If he becomes the next Brock Holt, that's important, too, especially on a team that fills one roster spot with a DH only player like JD.