IF Kingery has fixed his swing, AND can incorporate his improved plate discipline, he could be one of those "breakout" stories that happen every year. He's still got plus speed, and in the age of 95 MPH FBs being standard, a short compact swing making contact with the fat part of the bat is all you need to generate consistent alley power and 15-20 HRs.Big ifs, but the upside is there where he could push his way into the lineup.
It's also easy to forget that Sosa put up a RC+ of 104, .735 OPS, two years ago. His problem is he's a free swinger, and ML pitchers figure that out and exploit it. But if you can teach him patience, the pop in the bat is there, and with his fielding skills, you don't need a great hitter to have value [3 WAR in 516 PA over the last two years primarily due to fielding].
I'd be more skeptical of Cave, RC+ 85, 50, 81 last three seasons off the bench. Partially driven by low BABIP, but he has always had a high K rate (30+%).
Harrison on the other hand, even though he's 35, has put up respectable numbers in close to full-time duty the past two seasons, RC+ 104 and 98, plus fielder, so it's a good bet they can get a solid season from him and he provides insurance against injuries. Consistent but limited.
I think there's another level to Hall, ML BB/K 3.5%/31.0%, last two milb seasons: 11.7%/21.2% and 9.5%/22.6%. So now that he's had ML experience, he should be less anxious at the plate and more selective. Other than that, his ML stats last year are almost identical to his AAA stats.