There is just no progression when the series has as many left with one week to go as used to start the series. The numbers don't dwindle enough for dynamics to change and therefore this format has the house split pretty much along the same lines in the final week as it is the first, especially when producers protect big characters from eviction rather than realising some of those characters actually need to go for the greater good.
A show with 9-10 HMs in the final week isn't hugely different to show with 16 HMs, but get that down to 6 and how housemates have to interacts with each other really changes.