The best solution to your theoretical problem is to maximize skills so as not to wreck in the first place.
Too bad that doesn’t always work.
If I start feeling guilty, I'll tithe or something
You were raised from a completely different set of moral values.
The thing about an umbrella and why they are cheap is that the kick in after all of your other coverage is exhausted. So you have to have all your cars and house etc. with the same company and naturally you either need to meet their minimums or of course the umbrella rate would need to be raised.
Having an insurance company on the hook for over a million due to your actions, will mean you will have a vigorous defense at their expense. Then they have to pay the bill not you. Don’t forget that not only current assets can be lost but future income and assets too. Just makes much more sense to be protected.