Architects obviously run the gamut (like all professionals, for the most part) from good to exceptional, but as a general rule architects can add value to a project by: -Greater construction efficiency-Superior aesthetics/design-Understanding of regulations, codes, variances, etc (above and beyond a GC)   -Speed & efficiency-"Green" design or "Future-proofing" your house-A more holistic approach to the project or superior experience. 

Looking at a portfolio from a holistic point of view, The ideal allocation I like is 50% real estate, 30% your own business/investing in private businesses, and 20% stocks.That said, without leverage, the S&P 500 will generally out perform the real estate market in the LA and Atlanta as your can see from my chart below.I also agree with @ J Scott that you must specialize and focus, rather than diversify.

They're all related and you ought to take a holistic view when evaluating whether these schemes are actually worth the trouble.  

Yours only fits some, but then falls apart when you look at the data holistically and look at the states that are blue and yet have lower housing prices.

I think it's worth making the distinction because I can eliminate a property that won't fit my buying criteria a lot faster with the former than with the latter, but Michael Blank's is a lot more holistic and includes nice stuff like different classes of equity and their respective returns, etc

Hopefully you are able to find a lender that will take the time to understand where you're coming from and look at your situation holistically. 

I would advise you to have a holistic, comprehensive view of your wealth building process. 

This holistic screening has really improved the quality of tenants they've put in my properties, and has also helped reduce turnover dramatically

You can draw inferences from more holistic data, but this is a pretty Stretch Armstrong level stretch to me. 

But wanted to give a holistic answer.