Inverarity is not a Scottish village

Isn't it also sometimes more tactically advantageous to wound, rather than kill? A badly hexed or wounded wizard needs immediate help on the battlefield and ongoing medical care. If their allies lose or have to leave them, they become a new bargaining chip and potential source of information. Also, leaving behind people who are even half as traumatized and incapacitated as the Longbottoms is a blow to morale that death and new martyrs may not be able to equal.