I see it every now and then. For example, I was put into the Fargo system at a 380 a few years back after I had been playing maybe a year or so. The guy who put me in is a certified CSI/BCA ref, you've maybe seen them on the TVs here and there reffing. I was playing a fargo-handicapped tournament and he was familiar with how I played, and said that it would be a fair score to go in as. I didn't know. I didn't care. However, in our league play, new players without a Fargo go in at a 525, I believe. Obviously, if they're a player around a 400 caliber, after a season, their average starts to reflect that as it goes down. Then you have a guy like me, who doesn't play but one or two Fargo tournaments ever, entered in as a 380, but is maybe playing well above that by the time they hit league. Then you're seeing a 380 mop the floor with a few 500s.
So it depends on where people are in their own personal games when they start.
For another example, I know two players, one trained the other. The trainer never had a fargo, mainly gambled, but then started playing leagues around the same time as the trainee. This was 15 years ago maybe. Trainer is currently around a 630 fargo, trainee is around a 570 fargo. Trainee has almost entirely caught up to trainer by this point, and they're about even. But when they both started out, though they probably entered into the fargo system around the same score, trainer was already at the peak of his game, whereas trainee was still early on in his development. So trainer climbed quick, trainee took a lot of bumps while improving. I'd argue from what I've seen, both trainer and trainee being at 620s would be about right.