You are CORRECT, modern engine are DESIGNED to run this way, it oil temp that the important number (178ish or so is the sweet spot for engine longevity in modern engines). You can reduce your engine life by a LOT by running too cold.
One of the guys over on a Vette forum I'm on was part of the design team for the C5 and worked on this.
Read post # 15
160 or 180 degree thermostat ? - Corvette Forum
Since the hemi is very much like the LS engine, I think I would defer to people that ACTUALLY KNOW vs. old hot rod voodoo.
T-stat's do not have a lot to do with steady state temps anyway, it's fan setting that do. A colder t-stat will just keep the engine from getting to temp longer. Run cooler, kill the fans faster and all for nothing. There are time and ways to use them but you have to monitor oil temps and if it's your daily driver, you might have to change t-stats twice a year.