This is actually two questions: (1) composition and (2) size. No comment on (2)--but would offer on (1) composition that one has to examine each foreign contingent individually. As you imply, it is simplistic and inaccurate to simply rely on the old chestnut that 'more foreigners = decline in quality and more French = better'. The presence of non-French contingents certainly created challenges (most surmountable with adequate command attention) and, in some cases, serious frictions (real and imagined/exaggerated), but humbly submit that these challenges were peripheral irritations/detractors, not the major factors in the outcome of the campaign.