McDavid

That's a 1 for 1 trade, no matter how better McDavid is than Matthews or any other top 5 player (maybe even top 10 depending on age).

Close to 1 for 1/2 pieces is probably Bedard level talent from the draft+roster player.

3-pieces is probably a top 10-25 player.

If the Oilers want 4 or 5 pieces, they trade him for futures+1 roster player.

4 years of McDavid vs. 2 years of Matthews, don't think it's a 1 for 1, Matthews salary will outgrow McDavids in those last 2 years, a premium to be paid for salary control, and a premium for risk of departure is implied.

The point is the Oilers won't get McDavid's value in that type of trade if in any at all. They either take on the risk or get a massive package of futures.

The only way I can see the Oilers getting more on top of Matthews is if it's next season and both McDavid and Matthews want out but again it will still be close, similar to the Dubois for Laine trade.

For every Gretzky trade that returns futures, there's a Coffey trade that brought Shanahan to Detroit.

Stars don't get traded often, so, there's an equally small sample size to both support and refute your position.

I could be wrong but I think at the very least McDavid as the best player of his generation (and the now) if he's wanting out, he would be traded 1 for 1 regardless of contract situation if it's just about term in:

1) in a trade for the best goal scorer of his generation (and the now) in Matthews
2) the best defenseman of his generation in Makar

Potential 1 for 1 trades, although less likely imo, would need to factor in age and contract situation:

1) a trade for MacKinnon or Kaprizov (assuming he's a top 5 player).

2) Generational talent like Bedard after proving they are the real deal assuming this situation happens in the future. (in this case McDavid could be passed on).

Of course, one GM could fleece another in reality if it were to happen, and it could very much be a more balanced trade by adding multiple pieces on both sides etc...