Not every task merits training, but if consistently-high performance will prove beneficial, training is necessary.
First, training is an organized, programmed, on-going process directed at improving capability. This requires the means to measure skill and/or ability and must be measured periodically to determine if training is working as shown by improved results. Instruction (an introduction of concepts via class, book, video, or other medium) followed with hands-on work is only training for a person new to the ideas, a novice (someone without demonstrated, measured, higher-level skill), or a person in need of a refresher. It ceases to be training beyond novice skill levels and can not elevate skills further until actual training is organized and followed.
Changing a car tire is a useful task. For most commuters and patrol officers, it does not merit training so instruction will suffice. Knowing how to do the task and having demonstrated it once or twice is probably enough. The only retraining needed is a refresher of where the jack and spare are stored. A flat tire delays travel or stops the pursuit and a tire change will take many minutes. Training to reduce this tire change time by 10 seconds effectively gains nothing in this context.
For a NASCAR pit crew, reducing tire change speed by 10 seconds provided a huge advantage. Today, pit times are in the 12 second range. A coach with proven results of improving pit crew times from 13 to 11 seconds will enjoy lucrative employment. For them, a tire change is a time-critical task and training the task is beneficial.