I've never really considered bucks to be more savvy or harder to kill than does. What I do believe is as the deer ages, regardless of sex, they do become more aware and cautious, thus harder to kill. I kill a whole lot more does than bucks because I see a whole lot more does. And while I'd rather have a buck for more meat, (and the antlers are cool), I'll take a big doe as opposed to a small buck.