Georgia's 'backing' dancers were very distracting, and I suspect the deeply offputting plodding in front of the camera affected the viewer's enjoyment enough that she lost votes - it may have been the difference between her escaping the dance off, but we'll never know. I loved her foxtrot, but hated the staging and the lumbering dancers!
Kellie and Helen's dancers were similarly intrusive into their dances, and actually impacted on what those dances ought to have looked like, IMO. Kellie's VW massively lacked content in order that she could mess around on the table top kicking tankards and other time-wasting (but, no doubt, crowd pleasing) stuff! As for Helen, putting her in a long line of paso dancing people really exposed how not-terribly-good she was at those moves!
Only Anita and Katie's dancers were kept as more decorative elements and, in Anita's case, provided a fantastic moment in the dance where she performed solo with the 2 female backing dancers. That looked great, and felt very faithful to the original musical without losing too many AT elements!
The fact is, the number of dancers that suited Blackpool's huge ballroom floor, and worked for those numbers, was completely inappropriate on the relatively tiny TV Centre studio floor. That's the producers' fault - the rehearsal stage should have been the point where they shed dancers, and kept the floor clearer for the couples to shine.