No one knows. Doug Pederson will be the Eagles' next head coach, and no one knows how he'll fare. Again: no one. Anyone who says anything else is selling you a knockoff Rolex.
People will pass their judgments, of course. People who have played with Pederson when he was a journeyman quarterback, who have coached alongside him, who have talked football with him, will endorse him. People who follow the Eagles and root for the Eagles will hope for the best with him. Their endorsements and hope offer no tangible indication of whether Pederson will be a good head coach or a bad one.