The biggest surprises are probably Eric Hurley being ranked #1, and Arias down at #8 (although Sickels has been pretty clear in the past that he's not a huge Arias fan)...
Sickels also mentions that the Rangers have a deep group of grade-C prospects that he thinks could be sleepers, as well.
The depth of the Rangers farm system is something that is commented on fairly often by those who are familiar with these sorts of things, and I think highlights a point that is oftentimes overlooked or not really focused on.
Obviously, fans are more familiar with their own prospects than those of other teams, and the casual fan oftentimes tends to overrate his team's farm system because of that familiarity.
Sometimes, though, I think folks who are aware of this inherent bias, and are very familiar with their team's system, tend to overcompensate the other way...a tendency to know more about guys leads to a greater awareness of their flaws and limitations, which causes the savvy fan to downgrade a player. But because we are more familiar with, say, Josh Rupe than we are, say, a Chuck James or a Tom Gorzelanny, and are more cognizant of his issues, we may tend to downgrade the farm system of the organization as a whole moreso than we would otherwise.
And at the same time, there is sometimes a tendency to think that every team has a bunch of Brandon Boggses and Kei Komenanis and Rashad Eldridges, fringey-type sleepers who could do something but likely won't. Which is why I think it is important to give some credence to the true existence of this kind of organizational deepness when it is acknowledged by outsiders.
More importantly, though, is a philosophical issue of the value and relevance of depth. The Rangers' biggest weakness is clearly its lack of blue-chip type prospects. The organization is, in fact, almost reversed from where it was a half-decade ago, when the Rangers were very top heavy, farm-system-wise. If you look at the organization in late 2001, Texas had Blalock, Pena, Teixeira, and virtually nothing else. Go back a few years earlier, and the system was still top-heavy, with two heralded prospects -- Ruben Mateo and Fernando Tatis -- and little else of note.
Now, the Rangers don't have anyone even close to being as highly-regarded as any of those five players were. They don't have anyone that you can point to as a legit potential superstar (although there are some arguments to be made for Ian Kinsler).
But what they do have are a bunch of guys in the system who are good bets to be major league contributors. You have a lot of guys who, at some point, should be able to come up and contribute in the bullpen, off the bench, as a decent major league regular, with a couple of them maybe beating the odds and actually becoming All-Star caliber players.
The question then becomes...which sort of farm system do you want to have? Do you want to go more with the, say, John Mayberry Jrs., who have a good chance to completely flop, but who also have the tools to put it all together and be a future superstar? Or do you want to go with a Thomas Diamond, a guy who will probably be a quality major leaguer for a lot of years, but a guy whose "star" threshhold is pretty low?
And I think a lot of that ultimately ties into how much money you want to spend on your team. For the Yankees and Red Sox and Mets, it makes more sense to focus on high-ceiling, maybe-superstar-more-likely-bust type prospects. If you are going to spend $100+ million per year on payroll, you aren't going to have much room on the roster for young players breaking in. And you are probably going to be in a position where you are going to want to move prospects to get veterans back, either in the offseason or at the trade deadline...
And the prospects that are going to bring the most in return are generally going to be the Joaquin Ariases and Eric Hurleys of the world, rather than the Ian Kinslers and Josh Rupes. The guys who probably aren't as safe a bet to be successful, but who are viewed as having more star potential.
Having a deep system with less of the high-ceiling types is going to give you less ammunition to make the big, splashy move. It is going to be a lot harder to make a big trade with your prospects (although as Billy Beane has proven, it can be done).
But it also will generally mean that you've got plenty of cheap contributors from within that you can rely upon to fill out your roster. It means that you shouldn't have to go spend $6 million over two years for a mediocre setup man in free agency, because you've got several in-house candidates that can do the job just as well. It means that you don't have to go sign a Raul Ibanez to a 2 year, $11 million deal to be your DH, because you've got a Jason Botts who can be as productive for the major league minimum.
It means that you aren't having to go the route Doug Melvin was forced to go in the late-90s with the Rangers, spending money on the Mark Clarks and the Mark Petkovseks to be role players, because you can generate those players from within. And it allows you to allocate more funds to the difference makers.
The point of all this is, having depth in terms of decent prospects, like the Rangers have, isn't worthless. Having guys like Scott Feldman and Wes Littleton and C.J. Wilson around means that you don't have to go and overpay for a Dan Miceli. It allows you to devote resources to other areas. And while the breakout star potential is lower, you still can have a Michael Young, for example, exceed expectations...
Anyway, this is just some food for thought. I know some folks get more excited about the projectable guys, the guys who you can see, 5 years down the round, maybe developing into something extraordinary. But there is also value in having a lot of guys around who likely won't be great, but who will be able to contribute to a winning team.