Possible Clues:

• Move about quickly, shedding pounds to get in better shape
• Along with Turner, one will keep it in better condition
• More suitable for one on the assembly line
• Healthier mechanic
• Mechanic
• Better trained as someone to repair the machine?
• More qualified
• Told of being left cutting the long grass
• And Turner, as a tradesman, could have been in better training
• Assembler; more suitable