Again its about your wife not your wifes children. When do her interests play a part? When the needs of her children have been met. The needs of her children are to see their father. Something you/she is being selfish over.
I might agree 5 days notice is not great notice, and in an ideal world it would have been nice for there to be a conversation about changing the agreement, so you had time to alter your family time etc.and indeed prepare the children for the change in routine. EOW is pretty standard, and its designed so that both parents get weekends so they can have family time. I understand your situation is slightly different because you've made friday your weekly family time, but as i and others have said both sides have to make sacrifices, hes sacrificing his sunday you are unwilling to sacrifice your friday.
You say ots your wifes right to protect her quality time with her children, it is not her right to prevent her children from having time with their dad.
As to why cant he have all three children, i think you've answered this but how old is his daughter? Considably younger? More reliant on him. I'll give you a senerio how would you feel if the boys came home and you asked did you have a nice time with dad and the response was well he wasnt interested in us because "little sis" was there and every time she cried he had yo cuddle her, change her nappy, she threw a tantrum etc. This indeed wouldnt be ok.
So hes saying to prevent that situation that he cant have the boys at a time his attention would be on her. I don't know but that doesnt seem massively unreasonable.
You keep on anout reducing contact, hes not hes changing contact.
You keep saying why does he get to dictate something thats only suitable to him why do you get to dictate something thats only suitable to you.
Alsi staying uo late on a friday is part of friday its fun and its him that has to put up with tired children not you