Alright so you can apparently do this at an earlier level than what I was but this is how I got this achievement.
Player Used: Buttons Bunterson
Bunterson's Starting Stats: Power-28, Contact-60, Speed-58, Fielding-58, Arm-58, Mojo-48
Gear: Cloud Stallion Cleats (Sliver +22 Speed) and Diamond Earrings (Gold +20 Arm)
Train: Sluggerade (Gold +10 Speed and +10 Fielding) and Spiked Sluggerade (+17 Arm, +7
Speed, +7 Fielding, -7 Contact and -7 Mojo)
Coach: Umpire Diplomacy (+28 Fielding)
With these items being used there will be 1 open Coach slot as well as the Style slot.
Bunterson's Final Stats: Power-28, Contact-53, Speed-98, Fielding-100, Arm-95, Mojo-40
After applying the Coach item your achievement should unlock! If you know of a build that you can get earlier or know another character that you can get this achievement with let me know. Good luck!
PS: This is my first "guide" so if anybody has any tips on format or wording let me know!