I think the only really viable way to get a player of that caliber is to draft one, in the Top 4-5 of the draft. Apart from very rare circumstances like Tavares and his pajamas, players like that who are established in the league just rarely ever become available. Trading for someone like that will take more than a few third liners and picks.
Here's the thing, in 10 full years of GMing MacLellan has drafted, traded for, signed, claimed off waivers, poached from NCAA, smuggled into the country inside a horse carcass a grand total of ZERO forwards, defensemen or goalies of franchise or even perennial all star caliber. Z-E-R-O. That's 10 offseasons/seasons to work the phones and 70 draft picks to play with. That is a statistically impressive level of futility. Every single cornerstone player we have had from 2014 through 2024 was from McPhee. Even all star Tom Wilson was McPhee (who also got Filip Forsberg in the same draft. Yeah he immediately flushed him down the toilet but he's still a much better player than anyone BMac has brought in). Even Pittsburgh despite being anchored by their franchise players as much as we are still found Kessel and Guentzel in that time frame. The closest you have for BMac is TJ Oshie (great player but he has never cracked 60 points and cracked 35 goals once. Love him but he's very firmly a support player and has a Boone Jenner type career if he's your top dog), Dylan Strome (jury still out but he is firmly not in the Ovechkin/Backstrom/prime Kuznetsov echelon at this point even though he's getting better), and Matt Niskanen on defense (good #2 but no Green, Carlson). He didn't draft one single Roope Hintz, Jason Robertson, or Wyatt Johnston (all stolen by one single team since he was GM). No Tage Thompson, Jordan Kyrou, Robert Thomas, Vince Dunn (again same team even if half of them left). No trading for Eichel or Stone or signing Pietrangelo (all done by a single team basically run by McPhee lol). No dumpster dives or waiver claims of Verhaeghe or Forsling or Montour (again, single team that found several other elite players in the last couple years). You may think Tavares's pajamas are rare but I can point to virtually every team having gotten multiple players closer to the Ovechkin/Backstrom/Kuznetsov/Carlson echelon than the grand total of zero that have graced the caps roster for even a day since BMac took over. Even Jim Benning fell ass backwards into JT Miller and the idiot that was Jim Botteril still somehow got Tage Thompson (not counting the 1st overall Dahlin since anyone could have done that). We had a very good chance to trade up for Michkov (I really doubt Phoenix was married to picking Simashev with the 6th overall instead of the 8th overall and they were the top team in the league to stockpile freebee assets by far) but BMac stuck to his history and while we likely got a pretty good player, he would have to utterly explode in his development to be in the Ovechkin/Backstrom tier rather than the Oshie/Wilson one.
I don't know about you but if I see someone working for 10 years and they have a track record of
ZERO of doing a certain thing I don't exactly expect them to suddenly be good at it. He's very firmly a round out a star roster by paying market/over market value for available players with pretty firm ceilings kind of guy, not a pick out a diamond in the rough kind of guy. The kind of return he put up for Mantha other orgs get Reinhart or prime Kessel. Thats just who he is and has been since the middle of Obama's second term. Which is why I would very much like for him to try and land Marner instead of plying the same trade that got him 0 in 10 years.