I wouldn't say Bernard is STRICTLY better, def the most important stat and Leeanne has more after affection while giving up some hp and att, also on that note easier to 100% affection Leeanne than 100% trust Bernard. If you don't mind using dupes, they're close enough that I'd just use all Leeanne only because you've already invested fodder. I don't know of any maps or common situations where you'd ever want to have a third heavy leveled up but maybe someone more experienced can correct me on that.