I keep reading that for every "unit" (I come from the French version of the game, but there is nobody on its area ; I guess "unité" is "unit" ?), so I read that for every unit, which seems to mean: every single soldier, you need 10 chamans and/or 10 quipukamayocs. So in a battallion of, say, 85 archers + 15 atlals, you would have to bring 1000 chamans + 1000 quipus (assuming you want to proceed with a competent medical staff).
Either there is an error there (such as an improper translation from English to French, where it is normally 1 medic for 10 soldiers), or Mayans medics and mathematicians are supposed to be so awful that you need 10 chamans to heal 1 patient… (they forst fight among themselves, and the one who stun all the others gets to heal the patient). 
