I have read for a bit this post and a previous one with the same topic with I believe the same person starting the thread so I thought I would throw in my 2 cents.
I have never met Chris, but I have been a broker in Memphis for several years and deal in the same business as his company. I am certain we know many of the same people and I can say that he does have a good reputation around town. That's from a competitor, not an associate.
My thought in reading the OP is that the level of thinking isn't thorough enough to pass judgment on valuation. I am familiar with many of his listings and when performing properly I would reason that they could obtain those results. The consideration has to be made to whether the tenants will pay and whether maintenance and unexpected expenses will be a factor (theft/vandalism/eviction). Those are issues that unfortunately are prevelent in Memphis rental markets, ones that we obviously don't like to shed an emphasis on when selling a property. If you were to run numbers under an optimum scenario of collection of rents vs. normal maintenance the property probably performs as advertised. What has to be considered is the likelihood of that actually happening. While management is a factor in that result, the neighborhood and thus the related tenant base can give a good indication of the likelihood that optimum results can be achieved.
In evaluating the property and its related value, expected performance combined with the probability of those results being achieved lead to the valuation of said property. I do seem to see the mention of zillow and its valuation of the property. While some may use this tool, it is no substitue for knowing the area and the circumstances that actually contribute to the valuation, not just a computer formula. If anything, zillow may have contributed more harm than good with valuation, but thats another discussion.
While I am sure some properties havent performed, and he would probably acknowledge not all do as planned, his company must have a number that do with as many deals that they complete.
A better question may be what they do for the clients when a property doesnt perform as advertsied.