Not sure these guys' role in the conflict but would give more variety. I think you have quite enough French for the main units already. Though some cavalry could be useful in addition of course to the existing sphais. have you got an officer and trumpeter for them ? This is my only frustration with the range - one needs all the elements for a unit to come at the same time.
Thanks for the pict Cuirassier...but the cavalry in Tonkin is not, in my opinion, a must.due to environment, climate and above all tse tse flies or similar..some very few Chasseurs D'Afrique, made in a single occasion, a charge vs Pavillons Noirs and a kind of almost unknown mounted native unit or Tirailleur / Garde Cercle à cheval was created..even equipped with a lance i suppose for parade purposes..butdid'nt read any account of actions....maybe you could need, if you really want to have you cavalry amnong swamps, jungles and rice-fieds, a few casting of Chasseurs d'Afrique..In Tonkin they sported a native black kéo dress and usual French pith helmet...not very iconic but easy to convert for example from a Perry ACW rider provided with pith helmet..but if i was you i would buy 3 or 4 true Chasseurs d'Afrique from Gringo Mexican range in their true beautiful uniform and be happy..so you can use also your Armée d'Afrique cavalry for Maroc ecc...