This is completely realistic, so don't even think about claiming otherwise.
The Lightning keep Sergachev, Point, Foote, Katchouk, Raddysh, Cernak, and Ingram, while fleecing the entire League and ending up with Karlsson, Pacioretty, and Simmonds. Meanwhile, they dump the contracts of Callahan and Coburn, leaving them with $6,000,000 in cap space to re-sign everyone.
The Flyers are willing to trade Wayne Simmonds, and he would actually fit quite well with the Lightning's system. The Flyers ask for a roster player or good prospect, but Yzerman explains that his team has been elevated to the level where everybody is elite and untouchable, and offers a mid-tier prospect instead. The Flyers realize trading Coburn was a bad idea, so they take the opportunity to demand Coburn back to make up for it.
Bergevin then sees the growing powerhouse in his division, and decides to stop it by stealing Killorn and Stralman in exchange for Pacioretty. Yzerman throws in a couple of picks because he feels bad for him.
Matt Irwin isn't particularly good and the Predators don't really need him, so the Lightning trade Andreoff for a potential 7th D-man if Koekkoek isn't good enough.
The Senators initially ask for at least two of Point, Sergachev, and Foote, but Yzerman refuses. The talks end there until Karlsson tells Dorion that he refuses to play with anyone but Hedman. Callahan initially refuses to waive his no-trade clause and Ottawa refuses his cap, but then Yzerman outsmarts them by babbling about taxes until they're both convinced (come on, how hard can it be to outsmart Melnyk and Dorion?) . Yzerman offers that package to the Senators. Melnyk initially refuses, but, upon seeing the approval of Senators fans, immediately changes his mind and accepts.
The next season, the cap goes up to $81,000,000, giving the Lightning $30,339,555 in cap space to sign Kucherov, Point, Pacioretty, Simmonds, Gourde, Point, Conacher, Karlsson, Girardi, and Koekkoek. Because Cal Foote is ready, Girardi becomes expendable, and Conacher becomes expendable. Furthermore, the Lightning gain $5 million in cap space after Johnson goes to Seattle, giving them room to also sign Vasilevskiy, Sergachev, Cirelli, and Joseph the next season. The Lightning then win five Cups in a row.
Tad rediculous, don’t know why you wrote a short novel trying to justify this. Did you want the whole league while you’re at it? Killorn has an NTC so thats no happening for sure. You may as well of included a palat for crosby deal