The umbrella policy actually acts as a magnet for lawsuits. They can start with that, and go from there. There are complex asset protection structures that can be built, and insurance is very valuable in these areas. However, it is more valuable in life policies which are harder to get at.
The only way that I know to truly protect your home, is have no equity in it, making it worthless to a creditor, or have it in a limited partnership. The limited partnership is not bullet proof, but is a “reasonable” block to a frivolous lawsuit.
I am no expert in this area, but I have read a few books, and have friends who have set things up for themselves like this.