Insurance is not free money and you can't simply distribute risks among your tenants because the risks are correlated.
Like I said, you can tell it doesn't work because these businesses don't exist. There are essentially no landlords who own multiple single family homes. They do exist for multifamily and commercial.
I know plenty of people who own multiple houses. And plenty of houses that get rented and paid to the owner/landlord.
Insurance is not free money its a pool of money gathered from monthly payments together to offset risk. You don't need to distribute the risk over all of your homes you buy a policy for each home.
This stuff is 101. And works all around the world. There is even an app called airbnb that will find short term rentals for your house.