Ludwick was a regularly solid hitter in STL for many years, and would likely be upon leaving Petco. On the surface, this would be a great move. It clears the way in the outfield for Sappelt and Alonso next year, while giving us an immediate upgrade over Gomes and Lewis. Don't be skeptical that SD would take Heisey, either. He'd be cheap and under team control for many years, unlike Ludwick. As a rebuilding move, it works for them, and as a trade for a playoff push, it works for us.
I'm skeptical about signing a player that was on the Cardinals so close to the brawl, however. Bad blood and infighting is the last thing this team needs, regardless of how much Jocketty likes his former players.