As someone else who is short and skinny, this is a very dangerous assumption. I've trained in judo, karate, and wrestling, and gotten in a couple actual fights, so have some experience here. In a real fight for your life being shorter is a disadvantage, even more so if you have average length arms for your height. It's possible to overcome that disadvantage if you are more skilled than the opponent, but assuming equal skill you are likely to lose.

In an actual fight, going for a gut stab with a knife is one of the worst options you have. It means you are absolutely within grapple range, have done almost nothing to hinder their mobility, and even if it is eventually fatal, it often takes a very long time to die from a gut wound. You would be much better either going for a hit that would instantly kill them, or aiming for somewhere that would hinder their mobility enough for you to escape.

Also, in the real world it doesn't work like fencing, no one is going to break the fight up as soon as you score a hit. If you want to actually prepare for a fight you should try out a sport that doesn't break on point scoring. In general boxing, MMA, or wrestling would be a better option to prepare for a real fight that doesn't get broken up.

I'd almost recommend getting in an actual fight so you can learn how different it is from your imagination.

Take a real self-defense class. In reality, your size is not enough advantage to make up for an opponent's added strength and reach. Training and speed, however can bridge that gap somewhat, assuming your opponent is not on an equal footing, so to speak.

Okay OP. Okay. I'm sure you'll absolutely devastate someone by trying to slash at their jacket. Lol.

I disagree with your opinion. I think being the shorter person in a fight is generally a disadvantage.

All else equal, the person who is taller will likely have more mass, and thus have more muscle to utilize against you. They’ll also have a bigger wingspan, so their zone of threat is bigger.

When I used to study martial arts, my instructors always used to say “don’t bring anything to a street fight that you don’t want taken away and used against you”. Unless you have the element of surprise, and are using a knife that’s attached to your body, welding a knife against someone bigger may backfire. Being a master of de-escalation tends to have a better mortality rate ;)

That's interesting. Do you manage to land those hits consistently once the element of surprise is gone? I also practice historical fencing (but I mostly do arming sword and langes messer, though I've occasionally dabbled with rapier), and my experience has been that taller people usually have the reach advantage.

Ducking and thrusting straight ahead of you makes basic geometry work in your favour for compensating the reach disadvantage (your arm has a 90° angle giving you maximum range), but it also massively exposes your head of your first hit doesn't land, and prevents you from using footwork for a few seconds. Once your opponent's has figured out your strategy it would seem like he would just have to stay a bit out of reach and counter-attack/riposte while you recover from your ducking