[BurningFrog]

My reasoning is that a clock is either right or wrong.

The average of a right and a wrong clock is wrong. Half as wrong as the wrong one, but still wrong.

If this is a good mental model for dealing with clock malfunctions depends on the failure modes of the clocks.

[_qib3]

This is not how continuous probabilities work. The probability that a clock is exactly right is zero; hence there is always some error in a measurement of time. Adding additional clocks will always cause the error to be less or equal to the maximum error.