If you traded RNH for Byron and Plekanec that easily helps Edmonton contend right now, even if it's poor value. Your fellow Oilers fans in this thread have already said the difference between RNH and Plekanec next season is minimal.
Pleks and Byron scored 70+ points last season combined. They were also one of the best PK duos in the league.
If you ignore the fact that RNH is a 2C and Plekanec is a rapidly declining 3C ten years his senior, then sure, they're probably a little bit senior for just next season. I'd move a pick for Plekanec at the deadline but I wouldn't touch that deal as presented, it's a loser in the long run.
You also don't have me buying in with the last paragraph. Montreal was a middling PK team last year, almost a dead heat with Edmonton in PK percentage, so clearly we have guys capable of doing the same thing (Kassian, Letestu, RNH himself kills a lot of penalties).
Second, the total points combined thing doesn't make much sense either. Maroon and Letestu combined for 77 points and 43 goals, that doesn't suddenly make them worth Pacioretty or Galchenyuk, does it?
Many things have to be taken into consideration, and teams that throw away 24 year old top six centres for pending free agents and role players don't typically win much of anything.
Chiarelli's moves as the Oilers GM have all had one thing in common - they've taken the years to come in mind. When RNH does get moved I could see it being for a guy like Danault with a minor add here or there, not guys that can walk away. When he deals for veterans - like Talbot, or Kassian, or Maroon - he's the one giving up picks and prospects, and they'll be around for the long term.