I have not heard of these folks but you may very well be correct maybe there is only a handful at a time. 

Any other requirements on the seller to do this correctly ?  

It’s one of the mistakes many investors make by not titling their real estate correctly from the start.

Would I be correct in thinking of it that way?

Creating these complex structures from what I have experienced only costs me time and money and potential issues down the line to make sure documents are signed by the correct people and entities etc.

@Matthew McGillJust to confirm .... you will live in one of the units of the duplex, correct? 

If you were to buy a “basket” of real estate diversified over our entire country, then yes, you’d be correct.

Some of what they are saying is correct, like having a separate bank account to hold security.

Anyone who has actually been active in this space will know that borrower behavior can be predictable and irrational, and they might have a fundamentally different mode of operating their life than you do.Along with viewing the world your way, many think "their way" is the correct way so that is how it must be done.

She has been making mistakes sending the bill for premiums to the correct mortgage companies as well.