Frolik is horribly underrated, and he has chemistry with his line. Zucc is putting up far more points in NY right now, but on the Flames his ice time will be scaled back dramatically. Zucc on the 2nd line of the Flames would go from getting PP1 and about 20 minutes/night to being on a shutdown line with 15ish minutes a night (which is what Frolik is getting). It's not as simple as saying Zucc gets X amount of points on the Rangers, so replace Frolik and the Flames get X more points.
It's not a definite upgrade, and I'm not sure the coaching staff would disrupt the 3M line, who are a premiere shut down line in the league.
Even if Zucc does replace Frolik, we're looking at an upgrade on #6 forward for a 1st rounder...that's poor asset management.
I'd much rather see the Flames upgrade the 3rd line C, than push Frolik back into the bottom 6.
It is understandable that you haven't seen Zuc play that much, but he literally does everything on and off the ice. He is a pitbull that plays with a nasty edge, scores, assists and plays a great two-way game. The Rangers may not be very good right now, but his line with Zib and Kreider are one of the best in the League, and he has been an integral part of some very good Ranger teams that made deep run after deep run in the playoffs.
He would be a tremendous addition to the Flames. Your GM knows that and understands the war it will be just to get to the Finals. Some fans are going to be upset by what teams are going to give up for their post season runs.