Yes, I know. That's why I included all the cousins in my list of 'potentially invited'. Nobody is contesting that they might be invited or that they haven't know each other for a longer time - but length is not the only criterion (because why wouldn't Daniel Chatto be invited in this scenario as he has been in the family (much) longer than Camilla, Sophie, Catherine and Mike).
It seems that you agree that the cousins (including the cousins' spouses; not sure about for example the Duke's relationship with princess Michael) are more important than the grandchildren's spouses (who would also be there to support their spouse who just lost her grandfather) or the nephew-by-marriage. So, maybe... and maybe not. That will be up to the queen. Unfortunately, hard decisions have to be made.
N.B. My parents were recently excluded from the funeral of their brother-in-law whom they had known for (and had a close relationship with) their whole life (my mother) or over 40 years (my father) in favor of his grandchildren - which of course made perfect sense.