Is Andersen really an upgrade over Dubnyk?

Dubnyk fell off a cliff. He was like a Vezina contender a couple of years ago lol

Yes. Hands down.
Even in a "down" year this past season, his stats were much better than Dubnyk's on a team with arguably worse defense in front of him.
(Andersen 2.85GAA, 0.909SV%; Dubnyk 3.35GAA, 0.890SV%)
Plus he's 4 years younger, still in his prime for a G.

By extending Clifford you have to upgrade the 3rd sent to LA Kings to a 2nd

Good point. Forgot about that... In that case, I probably wouldn't do it.
Replace him with another cheap option on the 4th line.
Preferably someone who can skate but also provide some grit.

Although I say my team "sucks." The reality is that we actually kick ass on defense. And, no offense, but the Leafs are not good defensively. Therefore Dubnyk's numbers should be significantly higher than Andersen's. The fact that it's the other way around shows us that Dubnyk is now leagues behind Andersen. You know that soft goal Andersen gave up to Foudy in game 5? Dubnyk was good for at least one of those type of goals a game. Sometimes several.

So even though I don't personally like the trade, I can see Billy Guerin do this.