As effective as the Tiger Woods' coach is for Tiger Woods, he may be terrible for you to help fix that wicked slice you've got. 

Any investing strategy can work including adding bedrooms, but it comes with slicing and dicing up units that increases cash flow but decreases quality living space, and decreases the quality of the tenant pool.I like B+ class units with tenants that care about their credit score.

In just about everything they do, they take a smaller slice of a MUCH larger pie than one they could bake on their own.

Placing tenants that can't afford the unit is a terrible strategy any way you slice it, you are setting yourself up for vacancy and hassles with evictions, turnover, re-renting, etc. and as OP implied, not putting the tenant in a good position either.

Doing so can get you a slice of the general partnership pie.

You get your slice of the commission.

Secondly, they typically receive discounts from their wholesalers, which gives them a bigger slice of the pie while still costing the consumer roughly the same amount of money.

Slice a non compete agreement portion out of the Sales price.

You can get a much larger slice of the profits if you finance the homes, but that involves large amounts of capital and risk on your part.

Subdivision works best if you can divide by vertical slices, as opposed to up-down units.