From your original question, if you have some sort of idea in your head that the 4% rule has anything at all to do with rental property, kill that thought. Kill it dead.
If I've misunderstood you, even better!
If I had 20 rental properties instead of 3, I would have $1M invested in in them. Now, I've bought homes at steep discount that needed repairs, and the after repair value of those homes would be more like $1,600,000.
I would expect a gross income of around $192,000 if all were fully rented.
Net profit after expenses, set asides for repairs and vacancies, etc., would average around half that, or $96,000.
I could certainly expect to live on that $96,000 a year. Rents lag inflation (at least) by the length of the lease, so they would go up with inflation but not necessarily as fast as inflation. (Assuming you don't have a local area melt-down in population like Detroit.)