From what i've heard Chatfield was arguably Utica's best defender down the stretch and into the playoffs. I've seen him be compared to Tanev who was no doubt a surprise to have carved out an NHL career as well.
I don't know where your info came from, but it didn't come from Utica posters. I don't think Chatfield was any better than the rest of what had become the Comets top 6 after Holm was traded and not replaced. McEneny was out for the season and PTO Blujus became a mainstay. Sautner and Blujus became Cull's go to guys vs the opponent's top line, the PK, and key defensive situations. Wiercioch produced the offense for the entire bunch.
Both Brisebois and Chatfield made strides over the year. Both needed to be paired with a vet. They are far from NHL players, unless maybe they could get some call-up time for the bottom guys in Vancouver who are basically AHL players on most NHL rosters anyways. Neither have put up close to significant offensive numbers. Neither is strong in front of their own net and both lose their positioning when on the offside vs offensive pressure against. Brisebois is more susceptible to rattling under hard pressure along the boards. Both have coughed up pucks into very dangerous spots vs pressure, though Chatfield has developed a better solution in these situations. He has learned to just get the puck out of his end and live to fight another day.
These guys are very raw kids who are learning more every game. They would do better paired with more talented vets than Sifers and Wiercioch since neither is extremely strong defensively. Wiercioch was allergic to physical contact and was a stick checking maniac. Sifers has simply lost too many steps. Neither of these vets are serious role models for how the kids should end up playing the game in order to be NHL worthy.
A couple of vets who play the game the way you want your NHL prospects to play are necessary on every AHL team to set a steady game to game example for the kids to follow. The Comets did not have these guys last season. A strong #1 has been missing since Fedun in '15-16.
Robak tried his best in '16-17 and was the Comets best, but he was not a true #1. I think the hope was for Subban and/or McEneny to step up. They did a good job, but #1 was far from the level they attained.
I believe they were expecting McEneny to pick up last season where he left off in '16-17. Unfortunately he was lost to the season with a serious knee injury. Holm and Wiercioch produced offensively, but neither was a defensive gem.
We'll see what transpires this off season in terms of acquiring a couple of these better vets. There is nothing coming up through the Canucks system. They have to go out and get them. Brisebois, Chatfield, Sautner, and Sifers are all that are signed for next season along with McEneny, who can't be counted upon to be a key figure for at least the first part of the season. His rehab will determine his readiness in October. If re-signing Blujus happens and he is expected to be the key player at putting the D-corps on track, someone has badly missed the boat. He could be one of the 3 more they need. I repeat. A strong anchor to the D and a play making, puck moving offensive threat are essential to giving Brisebois and Chatty the best surroundings to excel and grow their game.