I did a bit of a comparison, using players that had over, or near, a .300 average (except Norfolk, because the only person who did only had 17 at bats...) and over over 100 at bats, along with their walk and strike out totals:
Jake Ring: 154 At Bats, 12 Walks, 46 Strike Outs, .318 Average
Chris Clare: 141 At Bats, 15 Walks, 34 Strike Outs, .298 Average
Ryan Mountcastle: 180 At Bats, 7 Walks, 32 Strike Outs, .328 Average
Steve Wilkerson: 155 At Bats, 19 Walks, 40 Strike Outs, .323 Average
Austin Hays: 165 At Bats, 7 Walks, 25 Strike Outs, .321 Average
Randolph Gassaway: 136 At Bats, 10 Walks, 22 Strike Outs, .316 Average
Garabez Rosa: 186 At Bats, 4 Walks, 32 Strike Outs, .339 Average
Austin Wynns: 133 At Bats, 21 Walks, 23 Strike Outs, .316 Average
Erick Salcedo: 146 At Bats, 8 Walks, 17 Strike Outs, .295 Average
Aderlin Rodriguez: 177 At Bats, 19 Walks, 32 Strike Outs, .294 Average
Johnny Giavotella: 171 At Bats, 21 Walks, 18 Strike Outs, .281 Average
Drew Dosch: 115 At Bats, 9 Walks, 39 Strike Outs, .261 Average
Chance Sisco: 122 At Bats, 13 Walks, 39 Strike Outs, .246 Average
Mountcastle might not have the least walks (thank you card sent to Rosa) or the most strike outs (enjoy the fruit baskets Ring, Clare, Wilkerson, Dosch, and Sisco), but he does have the second lowest ratio (hello again, Rosa) thru the system with that high of an average.
Two names stick out for certain things: Austin Wynns is tied with Johnny Giavotella with the lead in walks for this group. Wynns is known more for defense than offensive. Giavotella is known as someone that can get on base.
Sisco has a LOT of strike outs and a lower average for being a highly regarded hitter. Rosa has a really high average for someone that doesn't take a lot of walks and who strikes out a LOT.
Mountcastle will give you 4 strike outs to every 1 walk. Are teams pitching more at him, or is he swinging at pitches that would normally be balls? Even Wilkerson, who had 40 strike outs in Frederick, gave you 1 walk for every 2 he had.
Maybe some more batting cage time is needed?