Absolutely correct, and we know if it had been decided that William and Harry should not walk behind the funeral carriage, Harry would have complained that "he" was left out...never mind his brother and Charles Spencer would said the same about Harry.
I would think Sarah and Jane are appalled, as you stated, this affects them and their families.
It's been reported that William is absolutely furious at Charles Spencer. You know George and Charlotte are both old enough to learn about what's been written about their grandfather. Charles Spencer is a vile, arrogant, self centered little man. All he has is his newest wife for support and his identical minion Harry. He's lost any relationship with William forever.