I don't think we're slow, but we're not a team with particularly fast skaters, especially from a standstill. It would be good to add that element, and as you say and as
@Ola has said a ton, at center it's a real weakness. I'm not sure though that the whole personelle needs to change, or whether it's possible to rearrange the lineup in a way that helps mitigate that weakness. If you had Zibanejad, Panarin, and Strome all on separate lines, then you can attach wingers (and center) with the requisite wheels to their lines.
Lafreniere-Zibanejad
Panarin-Chytil
Kreider-Strome
Those are all pairings that could be, at worst, the basis of a good second line. Then you have your RWs: Kakko, Buchnevich, Kravtsov that can mix and match into it.
Personally, I'd love to see this:
Panarin-Chytil-Buvchnevich
Our three best even strength scorers all stacked together. Chytil has a lot in his game that's reminiscent of PLD who meshed so well with Panarin in Columbus. Between he and Buchnevich there is plenty of speed and strength to play low in the defensive zone, transport Panarin passes through the neutral zone, and to retreive pucks and create a lot of space and havok in the O-zone that Panarin would be able to exploit. Three players who can all pass and shoot, but especially for Panarin, two players who can put a lot of pressure on opposing teams, finish plays, and let him do his thing all over the ice.
Lafreniere-Zibanejad-Kakko
We need Zibanejad to play like a center again. He has it in him to commit to puck battles, cover for his wingers, and to win territory all over the ice. Playing him with the two youngest Rangers, who are themselves jam-packed with talent and creativity, might put that kind of onus on Zibanejad again. Between Lafreniere's dual threat as a playmaker and shooter, Kakko's boardwork and ability to move the puck to the most dangerous player (the player coming up the ice with the most speed, or who's opened up in the offensive zone), and a Zibanejad like the one in 2018-19 who is committed to making the right decision in every small play rather than flying the zone every chance he has, I think you could have the makings of a fantastic line.
Kreider-Strome-Kravtsov
Strome—by most any metric (and especially the eyes)—is not a traditional center for a shut-down line, but out of he, Zibanejad, and Chytil, I think he's the most promising pick for that kind of role. And to be clear, this isn't a traditional shut-down line. In some ways, I'd think of it as a decoy in that respect. What it really could be is a line that can get us out of our zone in a hurry. Strome has the vision, and as a RH shot, he can find and send Kreider easily on the left wing. Kravstov we've seen is a player who's harnessed the will to commit to details, but is capable of covering a ton of ice, not just N-S but E-W. It's a line with a lot of speed to burn and a center who can activate that speed.
You can have a team, for example like the 2016 Sharks, that aren't filled with fast skaters, but who control the pace of the game and always keep themselves a step ahead of the opposition because of the depth of talent, the creativity and intelligence, and the right compositions of particular skills meshed together. A team like that can always be on the attack because the attack comes in waves and doesn't stop. Hockey in 2021 might be a game defined by speed more than in the past, but it will always be a game defined by momentum. Speed matters less than whether you play on your toes or on your heels. And a roster like ours—filled with literal children and veterans who love to play pond hockey—isn't going to just fit together and gel that way from the get-go, but if given time and mixed together in the right combinations, I think they are plenty capable of becoming a force. Players can learn and realize that you don't need to score a goal to win a shift, you don't need to make a crazy play to turn the tide of a game in your favor: what you need is to support one another, pull in the same direction, and impose yourselves as a group onto the game.
Some Saturday morning hangover thoughts for you