Does anyone know how the MMP nightly rates are set?

For example in DC, the four Ritz Carlton’s are priced out at (all-in)

• $268 - Georgetown (Incl Estimated Government Taxes and Fees 36.53USD TakeCare Relief Fund (Optional) 3.00USD)
• $233 - Washington DC (all-in)
• $173 - Pentagon City (all-in)
• $174 - Tysons Corner (all-in)

These are, presumably, the lowest MMP rate you will find for each of these throughout the year. What I find odd is that from past experience, brands would load a predetermined baseline rate that was specific to that brand (ie during a trip last summer through Europe, Luxury Collection non-resort properties would all charge ~$174 all-in).

So what's up with these varying RC MMP rates all in the same city, on the same night?