I see what you're saying. Not only the complications of wording in the Will, but how any bank accounts were set up, and then how the Court may interpret the matter as a whole, and if that decision gets challenged.
This situation reminds me of what happened over 20 years ago in my family. My paternal grandmother had 9 children, but in her final days, only 1 of those lived with her and took care of her, so she left all her money, her farm, and family home to that one child.
She had one of the finest attorneys in her community draw up her Will, but it was nonetheless challenged by the other surviving children in a court case that lasted 8 years. The Will was eventually overturned, and her estate was distributed equally to all her children, meaning the home and farm had to be liquidated. After attorney fees, each heir got less than $25,000.