If you have 2 watches with let's say 5-minute difference, I have a pretty high confidence that the indicated hour is correct. The chance that both watches e.g.

If you have 2 watches with let's say 5-minute difference, I have a pretty high confidence that the indicated hour is correct. The chance that both watches e.g. broke in the same way is small. I don't think you will necessarily get a higher precision, but your confidence of the indicated time is higher.