I think you might have misunderstood.
When a player starts a new account they are rank 20 correct?
So if someone is ranked 60 and then start a new account they will start at rank 20 and be playing other low ranked players for a while till they get their personal rank back up to 60.
This is a twink player.
I don't know enough of how the ranking system works so I don't know how fast or how many games this person would have to play to get back to their old rank of 60.
There is no incentive to do this, and to be honest it isn't even actually a problem. So what if there are smurf accounts? Nobody is earning anything. The only function of rankings at the moment is better matchmaking, so people restarting at Level 20 are just setting themselves up to play with all the slow players at the low levels and wasting their time. Not to mention if they subscribed they are just wasting money. That is on them, not the system.
I checked out the top 50 to see if your fear of smurf accounts is founded. 41 of the people there I recognize either from the MF/Goko days or even as far back as isotropic. It's pretty natural for players who have been playing online that long to be good at the game. 1 is a confirmed smurf account (surprise, it has over 400 games, so your fixation on that number is meaningless) which doesn't even show up on the official leaderboard, so it doesn't seem like an issue. The rest, sure, I don't know them, but I have no reason to believe they are smurf accounts. Not saying I'm the best judge, but considering I recognize 41/50 users and I'm just one guy, it seems like we're okay here at the moment.
Out of the top 50, the only account I'm actually skeptical about besides the known smurf is aaaasn, who only has 4 games, but maybe he's just luser's good friend.