Mate, Penrith have won four with Dylan Edwards at the back, and while his game has evolved considerably during this time, I still wouldn't call him an elite attacking talent. Also, he's 29 and the most visible parts of his transformation as a player have happened over the last few years.
The game isn't as black and white as your painting it. Not every team needs a Reece Walsh at fullback to be successful, just like not every team needs a backline with 'elite speed' to be successful, which you've claimed before. The Tigers need to harness their individual strengths and play as a team to give themselves the best shot. Right now, they're doing the second part really well, and I'm confident with time they'll get the first part right too.