Hyman plays with McDavid because McDavid inflates his goal totals massively. With Leon, Hyman maybe scores 35 last year, not 50+. Hyman benefits massively from McDavid's ability to back defenses off on the rush and suck them in towards him when he is in the zone leaving Hyman wide open.
RNH sucks and has been sucking for a bit, this is the second season he's now on pace for sub-20 goals while getting the best deployment possible in hockey (tied to McDavid at 5 on 5 and full PP sessions). Even McDavid may not be able to get him to hit 20, but Knob won't let the love affair with this player go. Skinner should have been given a lengthy look here, he would probably have anywhere from 8-10 goals by now if he was given some of RNH's minutes.
If McDavid and Draisaitl have a valid criticism towards them versus say Crosby and Malkin, Crosby and especially Malkin worked better with a wider variety of wingers. Malkin led the Penguins to their first Cup winning the Conn Smythe with mediocre wingers like Max Talbot and the team got critical goals from Talbot. Later on he would be able to team up with players like Rust and still get great production, these aren't star players.
Leon hasn't really been able to find long lasting chemistry with anyone. Foegele is on pace to score more in LA than he did here with Leon, Arvidsson and Skinner both haven't clicked with him yet, Podkolzin is so-so in terms of net results, Evander Kane no longer really works with Leon and is largely now a bottom 6 player because of that. Didn't look like anything special with Holloway. Yamamoto + RNH were a good line for a stretch and then some how completely forgot how to play with each other.
We don't have money sitting around to bring in a Rantanen or Marner for him to play with, at this point what it is going to take to have some reliable offence at 5 on 5 from that 2nd line? Like who is the player we have to bring in and how do we afford that?