Yes, legionnaire ant definitely sounds more poetically bellicose . . . I love this list, btw.
sionnach - dulosis is a great word! and in fact some of the slave ants have become suffr-ant-gettes, killing their charges while rearing their own children. it's a jungle out there.
another animal worthy of the dubious distinction: Amazon ants . . . they capture slaves from other ant colonies in massive raids to do all their child-rearing and housework for them.