Being generous with your ~6 number to be either 5 or 7 houses you have either 7.8-11 people per unit?
That's slumlord territory and not any morally better than corporate landlords unless your average unit size is a 4 bed/2 bath.
Also there is zero world where you have 6 houses, 50+ people and can call yourself a small time landlord. That's being able to live entirely off of your rental income and a full time landlord. You could maybe, _maybe_ get away with describing yourself as a medium time landlord.
Small time is living in a 3 floor house and renting the other 2 floors, or owning 1 other home to rent.
I'm sure OP meant 6 houses with several units in it each, not 7-11 people per house. Otherwise the distinction between house and unit doesn't make sense.
This is a small time landlord. Large landlords have easily over 10000 units, and he is one half of a percent of that.
I hope he is able to live off the rental income. It's a big job to manage 55 units and keep everything in shape and administratively going, deal with turnover and so on.