There might be a confusion on what functions are taking place.

No Ellis, they aren't the same.LTV and combined loan to value is just one aspect.A purchase money second can go to 90% of the purchase/appraised value, being 80/10/10 for example for a homeowner, owner occupied, it's much different funding that to a flipper for construction or renovation, that's a different thing.Ability to pay, credit, collateral, remaining equity, use of funds, loan concentrations, amounts at risk and size of the loans all play on risks.

At times you need to use an account described for another function and adapt it to a different use, you can do that if you know the accounting function.As Steve suggested, if you do them, ask a question or have them reviewed, the cost should be much less compared to having them do the work, a question will probably be free.You time is valuable, it doesn't matter how many units you have, it depends on the time required for you to do the work.

How big is the living room you are combining?

Otherwise, if it's not selling, it may be other issues, like price, functionality, amenities compared to other homes (like no garage), etc.

The other is a point where three roofs combine to one gutter and in high rain it's just to much for one gutter to handle.

That's a bad combination.

I have one slab on grade and 7 finished basements with plumbing in the floor which would be the same thing functionally, no problems. 

I would recommend using a combination of an LLC and a land trust.

Consider factors like expenses, maintenance costs, management fees, and any potential risks or fluctuations in the market.By combining these steps with the data provided by AirDNA, you'll be able to make a more informed investment decision.