I once came in on a project where one dev used "func( arg )" and the other used "func (arg)". They would reformat each other's lines when they changed something, so the diff had a lot of whitespace changes. The two were not on speaking terms any longer, so I was tasked with cleaning up the mess.

First step was to run an autoformatter. I used stock presets so neither of the two would think the other was favoured in the cleanup.