People say unproven even with minor league numbers because they are well... unproven. Many players can produce in the minors but fail in the majors. Also, very few major leaguers are consistent. That being said, hitters are more consistent than pitchers, and one good hitting team is usually a good hitting team the next year.
Yes, there are alot of question marks on the Cleveland team, but with so many players with huge upsides, if only 2-3 meet potential that line-up will score some runs. Counting on Gonzalez to be injury-free is a little too optimistic... the guy's career is most likely over.
...Boston papers now and then suffer a sharp flurry of arithmetic on this score; indeed, for Williams to have distributed all his hits so they did nobody else any good would constitute a feat of placement unparalleled in the annals of selfishness. -Updike