Gaucher is definitely the biggest impact on that line if you have been watching San Diego games this season. That's not to take anything away from Caufield, but Gaucher is the one that is first on the forecheck and is applying the pressure and pretty much setting the tone for the line, while Caufield is typically more around the front of the net.
I said near the start of the season I could see Caufield as a 4th line / 13th forward at the NHL level in the future (granted more likely to be an AHL lifer). His big problem is his puck skills are not great at the AHL level, let alone the NHL level. He needs to improve on that for me, maybe a small cup of coffee at the end of the season as a 4th line energy forward but there is no way he can replace a player like Leason at the NHL level right now, in terms of I don't see him capable of playing 13+ minutes a night effectively.
Myatovic has 5 points in 7 games since being put with Gaucher/Caufield. I have missed a couple of games (the Tuscon series) but he was with Gaucher/Caufield since the Barracuda game at the start of the year and I don't believe he's been moved off that line since from the games I've watched. It's good to see him producing, but maybe not a surprise as the third forward has produced very well on that line all season (Sidorov was the same).
Carpenter/Nesterenko/Regenda are the three biggest disappointments so far for me. Especially Carpenter who is one of the worst vet forwards the Gulls have had in the last few years.
Sidorov, Pasta, Colangelo all have potential to be middle six forwards at the NHL level. It's not quite as glum as the picture being painted IMO.
Pasta himself has taken a big step forward (even if the production wasn't as high) in terms of his skating and ability to separate from defenders which is a huge sign as his hands aren't the issue.