All managers, in business and sports, make mistakes.
The good managers identify their error and fix it quickly.
I think Dubas is pretty close to that here.
With the loss of Hyman, I was all for signing Ritchie and his contract seemed fine under the circumstances, etc - at that time. For whatever reason, it didn't work out. With Ritchie clearing waivers in January, his trade value was proven to be worthless.
If Dzingel doesn't clear waivers to prove his trade value to be negligible, I cannot imagine him being worth more than a 7th - almost worthless after years of injuries and bouncing around.
GM Armstrong isn't stupid. I'm sure he's been shopping his UFAs. Bidding on Lyubushkin from other teams was lower than what the Leafs offered so he leveraged eating Ritchie's contract to a 2023 3rd or a 2025 2nd.
I don't think it was a steal by Dubas. Very roughly, a fair deal for both parties where Armstrong maximized a return for his UFAs, offset some salaries cash on two players and took a gamble on whether a change of scenery could turn around Ritchie's career.
I doubt Lyubushkin is a true top 4 on a contender. But he is somewhere between a 4th and 7th. He provides depth for sure and the defensive physical ingredient. But I think the biggest need is for this D Group is Muzzin needs to get his game turned around. I'm not sure if it is a nagging injury or what. Maybe Lyubushkin helps give Muzzin a break.