In this specific example the 4 rental homes likely don't even pay for themselves. Add up the mortgage, insurance, maintenance averages, and property taxes then divide by units and subtract the average rent (include vacancies in the average): that's how much you make per tenant.
At most I could see a profitable location with 4 units covering groceries and vehicles, but not vacations. You would need more like 8 or 9 units for that. Bonus points if they're combined into a single building to reduce maintenance costs and save on heating.
This meme seems to specifically target mom & pop level operations. If the Tenants are really such victims they should just get together buy the property out.