For the opening game, I think the forward lines should be:
RNH - McDavid - Puljujarvi
Obviously the duo was amazing for their stretch last season, and I liked what I saw between McDavid and Puljujarvi last season. What I hadn't realized was how well RNH and Puljujarvi played together. Adding a fast sniper to an already amazing pair could make this the most dangerous line in the league.
Lucic - Draisaitl - Yamamoto
I've seen a lot of hope for Lucic and Rieder as Draisaitl's wingers next year. They both have no skill, passing, or finishing ability whatsoever. Replace Rieder with Yamamoto, and I think this line has the potential to be really good. Lucic and Draisaitl are both big and cycle the puck really well, and Yamamoto is slippery and can get open quickly for a scoring chance. I think this is Lucic's best shot at rebounding, and Draisaitl's best chance to have consistent linemates for the year. And for those saying that Yamamoto should be sent down for at least a year, I'm going go out on a limb and say he is easily the Oilers best natural winger right now.
Aberg/Cagguila - Strome - Rieder
Definitely not too high on this line. At least the wingers bring some speed to the table.
Khaira - Brodziak - Kassian
Love this line. Could be in contention for the toughest line in the league. All bring a good defensive game, some scoring ability, size, and are very hard to play against. All three of these players are good enough to step into a 3rd line role (imo) if needed.
One interesting experiment could also be to have Brodziak as the 3rd line center, bump Lucic down, and have Strome play the wing with Draisaitl.