With over a decade of martial arts training, Hacker is the undisputed queen of melee combat. She's proven herself capable of defeating every other merc in a square fight. However, those fights are not made equal. There are some mercs whose matches were hard-won victories and others that were never a contest to begin with. On a scale from 1 to 5 (1 being the easiest, 5 being the hardest), here is the definitive ranking of each merc's match up against Hacker. Note that these match ups are decided through physical prowess only—no weapons or environmental hazards to exploit.
Scout: He's definitely got a height advantage, and that makes him cocky. Overconfidence aside, he's naturally scrappy and lightning fast, but he frustrates easily if a fight isn't going his way. He's got a fair amount of muscle, but his runner's build means he's easy to topple. Predictable and easy to bait. One sweep to his legs or a sturdy grapple, and he's toast. Hacker has a tendency to underestimate him, though, and if he's smart enough about it, he can get a one-up on her. 3/5
Soldier: Easily the least predictable of the lot. He's got actual hand-to-hand combat training and a sizeable advantage in height and weight. They spar a lot, but he switches up his techniques often enough that she has to choose her moves wisely to get the upper hand. 5/5
Pyro: Without their weapons or environmental hazards to exploit, they don't fare well. They might get a one-in-a-million lucky hit, but they're the easiest merc to put down in melee combat. 1/5
Demoman: He's got height and weight on his side, for sure. His sturdy frame and reasonable amount of strength makes him dangerous if she's not careful, but his lack of technique makes him easy to outpace. He might be prone to sudden bursts of strength, but he's got a glaring blind spot (lol) to exploit. As long as she's paying attention, she can handle him. 3/5
Heavy: Like Soldier, he's a triple threat of advantages: height, weight, and experience. He might be slow, but he only has to catch her once. She has to be on her A game, or he'll easily wipe the floor with her. By far her favorite to fight. 5/5
Engineer: His stocky frame makes him hard to knock down, and he's got more power than meets the eye. He's more observant than some of the other mercs, which makes cheesy moves difficult to execute. His grip is surprisingly strong, and his grapples are challenging to get out of. If he were just a few inches taller, he'd be a much greater threat. 3/5
Sniper: He picked a job away from the action for a reason, but he's not a slouch. He has a significant height advantage and power to his punches, but he can be grappled or swept easily. Really only a threat if he catches her off guard. 3/5
Spy: He's got height and experience, but his old age means he's not as strong or fast as he used to be. His wiry frame makes him difficult to grapple, but it only takes a couple of powerful strikes to put him down. The greatest challenge in fighting him is accurately predicting his next move. 2/5
Medic: Height and weight are on his side. Surprisingly fast and powerful, but has a few glaring weak spots that are easy to exploit. Get him in the jaw, and he's down for the count. 2/5
Bonus! Miss Pauling: Relies on technique over power or speed. Lesser opponents might underestimate her, but Hacker knows well enough not to let Pauling get the drop on her. If she gets the upper hand, it's a challenge to wrest it from her. 4/5