1. Antonyms for Confrontational include nonConfrontational, nonaggressive, compromising, nonargumentative, nonbelligerent, unassertive, amenable, biddable, diplomatic

2. Antonyms for Contentious include peaceable, nonaggressive, nonbelligerent, pacific, peaceful, unbelligerent, uncombative, unContentious, agreeable and easygoing

3. Antonyms for Bellicose include peaceable, nonaggressive, nonbelligerent, pacific, peaceful, unbelligerent, uncombative, uncontentious, agreeable and calm