Kennedy as a top-20 is pure comedy. He's pitched well, but he just doesn't have the tools to get rated that high. His scouting report is remarkably similar to Clippard. Not overpowering, good offspeed stuff, good control. He's even having similar rate results, of course he's two years older than Clippard was down there. Hell, he's only 2 months older than Clippard now. Imagine Clippard against the kids in the FSL. Only thing is, Clippard didn't even make BA's top-100 this year. Good luck with that one.
Tabata came in at 27 on the BA list, but that was before the first hint of some tarnish on the resume. I've read reports that he has to report to the park early to ride the bike in order to maintain his weight. One of the funnier things you hear like dogma from Yankee fans is the quote from a scout that said he reminded him of a young Manny Ramirez. Who, by the way, was putting up an 1100+ OPS as a 19 year old. Great scouting report. He's going to have to do something with that .064 IsoD in order to move up. My guess is he slips, and without power, he doesn't come close to Ellsbury in speed and fielding.
Chamberlin is only one there I see with some realistic ceiling. Of course, he's the same age Buchholz was last year in A-/A+, and Buchholz dominated but only came in at 51.
To top it all off, what's with all this below AA talk? Oh, that's right, the Yankees no longer have anyone at AA or higher worth paying attention to, so that caveat no longer matters.