The Morbius Doctors were placed strategically between the Timeless Children and the Ruth incarnation. As you said, that was possibly the Doctor's attempt at ordering the faces in her vision (although, it makes no sense as to why she would choose that order) but that is complete speculation. We have to go with what we saw on screen, and what we saw was a systematic order - if we are to include the Timeless Children and Ruth as unplaced incarnations then we must place the Morbius Doctors too. The Other has nothing to do with that as of yet.