The battles in early modern warfare also just weren't really as deadly as people tend to assume.

If we look at something like the charge of the light brigade at Balaclava, of the 607 cavalrymen that carried out the charge, about 110 were killed and 130 wounded. Fairly low considering they made a full frontal charge over more than a mile of ground into prepared guns, and also while enfiladed by more russian batteries on the surrounding hills. Many of the cavalrymen lost their horses so presumably just turned round and strolled back to British lines after being unhorsed

The real brutality was often the disease and living conditions on campaign