He has no spouse. His only child died in infancy. His has a sister and five half siblings. His estate is likely to be extremely complicated because there is a lot of stuff that does not have an easily established value.
If he has half siblings I can virtually guarantee they’ll be the same as full blood siblings. It’s that way in most states given a death intestate. They are all co-equals.
I’m dealing with that now with my younger brother’s death.