All fair points. Barnes is older, but like you said, his velocity and stuff is K'ing 1.5x what Campos is K'ing right now with similar K rates, so I give Barnes an edge there because he's performing extremely well and dominating the hitters like an elite prospect should be doing to SALLY hitters (a la Bundy).
I place Kalish above him because we have seen him at the big league level having success at the age of 22. I can see how you wouldn't put Kalish above Campos, but I think if he didn't use up his rookie status he would be top 100.
Swihart has only played in 14 games, and this is his first year in professional baseball, whereas Campos had thrown 171 innings of professional baseball prior to this year, so I would expect Campos to outperform Swihart initially.
Either way, Campos is not a top 3 prospect for the Sox. He's would barely crack the top 5 when you factor Swihart, Bogaerts, Barnes, and Middlebrooks.
Henry Owens is another guy to keep an eye on. He's only 19 and is in his first season of professional baseball and having some control problems (6.75 BB/9), but he's got a ridiculous 18.56 K/9 thus far.