Eichel isn't that caliber either. Matthews is the second best goal producer in the NHL after Ovechkin. They're on another level.
Eichel would probably put up 50-60 ES points here and 20-25 on the PP (he'd play a minute or two less in Philly, he'd be the 2C for one thing, no, he's not as good as Couts). But that also reduces other players' minutes, so it's not completely a net gain. Say 30 extra points, that's about 12 goals (2.5 points per goal). Which is probably optimistic, given Eichel's pp/60 is similar to say TK or whoever is traded for him - so not a huge net gain. Nice, but it ain't going to turn this team from pretender to contender.
What will turn the Flyers into a SC contender:
1) fix the goaltending
2) solidify the defense
3) continue to develop the young forwards, Frost, Allison, getting Lindblom healthy, Patrick finding his mojo, Laczynski as an exceptional 4C who can move up, what do you think the cumulative impact will be?
The Flyers have eight forwards who score at a 1st line/top half second line rate:
G, Couts, Farabee, TK, Voracek, JVR, Hayes, Lindblom at 100%. (if you don't believe me, ask
@Appleyard)
Frost and Allison have that potential, and Laughton is close to middle 2nd line level scoring.
And Laczynski showed in college he has solid offensive chops, while if Foerster plays in the AHL next year, he could be pushing for a job in the spring.
Offense from forwards is probably the strongest aspect of this team.