How can overcharging or horizontal and vertical charging be employed as a strategy for discovering the truth?

Truth, Justice, and Charging
Overcharging, or piling on charges to trigger the acceptance of a plea deal, is a common practice in prosecutorial settings to get a defendant to accept a particular deal. Horizontal charging, or multiplying accusations, and vertical charging, or charging at a higher level than warranted, are variations of overcharging. Depending on your perspective, these strategies provide leverage to uncover the truth, or they force defendants to make poor choices, admitting to inflated charges. But is the issue that clearly delineated? In this Discussion, you consider similar questions.

Post a response to the following:

How can overcharging or horizontal and vertical charging be employed as a strategy for discovering the truth? When is it most appropriate?

By whom are the strategies best applied?

At what point does overcharging or horizontal and vertical charging become coercion?

Is the strategy ethical?