Jagr was not a dominant player against today stars, he was a good player in this generation, he didn't break a ppg in the NHL since 06, hockey sense doesn't leave you because the skill's diminish.
Having said that Lemieux would certainly translate to the modern NHL with relative ease. He's a 6'4 truck with a wicked shot. He'd be a very rich man's Getzlaf in today's game. Gretzky doesn't have a comparable in today's game because no one plays like he did. Free wheeling and slick passing has lost it's luster in today's NHL.
I know you all love Gretz and you all will defend him til you grow old. However, he was a product of his time period.
Goalies were averaging 3 ga, a game up until 1993, where we saw a significant decrease in output in scoring.
Lemieux scored 160 in 1993, followed by Lafontaine at 148, Adam Oates at 142, Yzerman at 137, Salanne and Turgeon at 132, Mogliney and Gilmore at 127, Robitalle at 125, and Recchi at 123.
Only Belfour, and Potvin had less than 3 gaa that season.
Now let's look at the 1994 season, a huge change as the goaltending and defense took a huge step forward in their abilities along with all the new franchises having a few seasons under their belt to really solidify their play.
In first we have Gretzky at 130, a 30 point drop from first place last year, Fedorov at 120, Adam Oates at 112, Gilmour at 111, Bure, Recchi and Roenick at 107, Shanahan at 102, Andreychuk and Jagr at 99.
Our goaltending was way better, Dominik Hasek had a 1.95 gaa as well as almost every goalie in the league being below 3.0.
This is where things get pretty different, the league doesn't see another 130+ scorer with Gretzky in the league until Lemieux returns from his cancer, to put up a staggering 160 points with Jagr as his winger with 149
However even he could not defy the game and where it was headed having a 120 point season the very next year. With Salanne being the only other player to break 100 points at 109.
The trend continued the next year Jagr led the league at 102, no one else broke 100. Jagr broke 100 and Sakic in the next few seasons, however no one got really close to going into the 120+ area.
I think I've laid it out pretty well here that the people thinking that Mcdavid wouldn't put up 180+ are kidding themselves. Along with most of the kids that play in the NHL today. The game is faster tighter, and there isn't room for those statistical powerhouses.
What we are seeing now is a few a rare few players that can break that 100 point barrier. I'd be shocked if anyone broke 130 ever again.