As solicitors, you can spend many hours working with your clients carefully crafting Wills which ensure the most effective and efficient succession of their assets.
I have met with a number of clients over the years who have selected specific charities to inherit in the event of a "family catastrophe" but they usually that they name the first charity which pops into their head.
I viable alternative might be to leave the distribution of your estate to such charities as your trustees select. You can guide them as to your wishes by identifying particular causes (e.g. children, dogs, LGBT+) and asking that they select charities to receive funds which would spend them most effectively.
A handful of my clients have even directed the establishment of a charitable trust in their memory via their Wills to ensure that their personal legacy lives on.
Most people don't think to think about "the worst" happening, but at least by preparing a Will, Mr Cousins' fortune will go to help those in need rather than distant relatives or even the government!
A multi-millionaire catering boss has left a "substantial amount" of money to Oxfam after dying alongside his family in a plane crash.