Emma H. answered 05/08/19
English Writing Assistant and Tutor
Because each scenario is slightly different but the number of people stay the same throughout, then I would say "The number of people involved are the same in each of the paralleling variations." This will clarify to the reader that the number of people does not change. Adding "... in each pair of..." would give the reader more information than necessary, as they can already imply that the parallels are in pairs. Hope this helps!