Maybe I'm wrong.

If you have 100K ins, they might pay the $100K happily and not defend U
at all,
since it could cost more than $100K to fight the case. You could
easily be
on the hook for anything $100k without any help.

If you have $1m ins, they will be interested in your case... they
wouldn't just
write a check for the $1m. Would be worth defending. They might reach
a settlement that would end the deal.

Seems like having them have LOTS of skin in the game is what you are
paying for. Bill