No matter how one spins it, a bank or lender owning a single family residential dwelling is not a "typical" owner or seller and is not selling the property for the same reason as a "typical" owner-occupied house is sold. Whatever is said, the bank is selling the property because it got ownership by default and not choice. The bank does not want to own the property and therefore when the bank gets rid of the property, it has a non-typical motivation for selling
I respect your experience etc, but in this case think your reasoning is not following the market...it is not a matter of "spinning it" The problem is twofold. First, from a buyer point of view, and one of the defining parameters for choosing comps, imo, THE gold standard for choosing comps, is the principle of subsitution. So, let's say your subject is a 1500 sf house with pool and lake view. There are fiour listings in the subdivision, all ( to make it simple) 1500 sf houses with pools and lake views. They are all on MLS- two described as owned by private owners, one advertised by realtor as a short sale, and one advertised as owned by a bank and a foreclosure sale. From a buyer point of view, all the houses are desireable and subsitutions for each other, and the foreclosure/ short sales might be bought first, assuming they were lower priced. Now, let's say there were six sales in the last six months of 1500 sf homes with pools and lake views. All were listed on MLS. Two were sold by owner, two as short sales, and two as foreclosures. Obviously, short sales and foreclosures make up a good part of this market and should be used...they meet the principle of subsitution and are ongoing in listings.
Now, the second part of the problem is what defines typical seller motivation. Truly, both a bank and a private owner's motivatins are the same...they both want to sell the property and are competing for today's buyer. So what if the bank got the property by default and didn't want it, and the house across the street is owned by a sweet couple who raised their kids in it and now are selling because they want to retire...both just want to sell at this point. Now, the bank may want to sell sooner, or not, then the retired couple. But how soon THEY want to sell is not the issue...the issue is, what is typical marketing time. If the pressure coming from short/sales foreclosures is, 90 days, because those homes slash their prices to sell in 90 days, then 90 days is typical marketing time, even though sweet retired couple can wait a year to sell. In this market, the sweet retired couple who can wait a year is the atypical seller, with atypical motivation...most of the market is desperate to sell their homes, and when they get realistic and serious, they slash the price enough to sell within 90 days. The sweet retired couple are now ATYPCIAL sellers, with a motivation atypical for this market ( even if their motivation was typical in the prior market)
For comparison,...let's say you have a rolex watch you owned and loved for years, and need to sell it, so you take it to a pawn shop. On the other side of town, a bankruptcy proceedign i under way too dispose of an estate's contents and among which is the same make/model rolex. The judge orders the contents to be sold and the watch is sent to the same pawn shop. The buyer who enters the shop doesn't care that you owned your rolex for 10 years, and that the other watch came from an bankruptcy proceeding. All he cares about is the condition of the watch and the price. Now both watches are competing for the same buyer and are equivalent subistitutes for each other.