Nice. Exactly. No good ever comes of it.
But it's so tempting to think if you exaplin they will understand why they are unreasonable.
They won't. They never will in their world they are completely in the right and they will never ever ever see any other point of view.
Trying to talk reasonably to them and get them to change their mind is a waste of time. You might as well try and turn the tide.
And the thing is. No one else will see it until they are on the receiving end. That's not their fault, it just means they are not the narcs victim. Yet. And that is frustrating. And used to make me so angry (with my mum and dad)
I don't have any answers. I don't have any magic cure. That sounds a bit depressing and I don't mean it to. All I can say is it gets better once the kids grow because you don't have to see them.
We used to do pick up and drop off via school at my insistence to minimise actual contact. It was a pain in the hole at times, but infinitely better than him landing to my door and playing silly buggers being late or not bringing half of what was needed or just generally fucking about.
So, if I dropped to school, he picked up. Or vice versa
The only other pieces of advice are those I've already given and learnt the hard way. Copies of correspondence. Texts. Emails. Always always have back up evidence and try never ever to talk face to face with them.
I am certainly not perfect at it, I learnt it the hard way.