To think this is NOT a fair split of holidays

[IBSworriescanitbe]

Genuinely, please let me know if I am BU
So usually in holidays me and ex split week and week about, Easter, Summer etc and it usually works out ok.
This Xmas he says he wants New Year week, ok... but he also wants them Sat 22-Monday 24th then to split the day on Xmas day and to see them on the 28th as it is the only day he isn't working that week.
He got mad at me when I suggested it wasn't fair (essentially it means he will have them ten nights and me four!?), he is a controlling bully which is why I left him in the first place.
I have suggested he can have them 22nd Sat - Monday 24 and we can split Xmas day, if I can then have them Thur - Sat in the second week, meaning we would both have a run of four days.
He is acting like I am robbing him of time with his kids.
I am so angry and part of me just feels like saying he can have the kids the whole bloody holiday, but that would be awful for me and them not to get quality time together as I work four days a week.
How can I approach this, he is quite volatile so kicks off easily :(
Or AIBU?

Do they want to see him more? Given you have far more time with them usually per week it's not worth falling out over four days.

If your original agreement was your preference, just tell him that it has been agreed and that you have already made plans with those dates in mind. There is a difference between being flexible and being a doormat. Do everything in writing and keep it for future court reference. Set your boundaries, but don't make yourself crazy. Life is short. When you argue with a narcissist, you can't win.