Jab can be used as the knock down punch if you put your body behind it.
Using your body correctly, with any other punch, will generate more knock down power. But, knock down power is not the point of a jab.
Since a foot sweep need to sweep down your opponent, it's like to knock your opponent down. You will find out it's much easier to sweep your opponent down by using your back leg than by using your front leg because the body rotation.
When I do a sweep, I use timing. Using timing is much more powerful, than using raw power. Using proper timing, sweeps take very little power. I sweep with both front and back leg. It depends on the situation.
You are still focused though, on one single aspect. The maximum amount of power. There are more aspects to consider. I can shoot my opponent between the eyes with a gun to stop him. I can use:
- 38
- 38 Special
- 9mm
- 357 Magnum
- 45 ACP
- 44 Magnum
- 500 Magnum
- 308 lapua
- 50 cal BMG
- 20 mm cannon round
The list goes on, each getting more powerful... but at some point on that list you have sufficient power in the round to stop the guy with a head shot. Yes, you can deliver more and more power. But at a certain point, you need to consider other things. How many rounds do you have? How fast to reload? How hard is the recoil? How fast can I put the gun back on target after shooting? Most importantly, what situation am I in? If I am in close quarters, inside, I might not want to have the 50 cal BMG, even though it will do a lot of damage.I would probably want something between the 38 and the 45, even though they are less powerful. The 20 mm is right out, even though it is the most powerful one listed, mainly because I can't lift it. But, put the guy out a few hundred yards, and I will take the 308. Put him out a 1000 or more yards, give me the 50 BMG. Let me be in a vehicle, and the 20 mm cannon looks better.
Look, the MT kick is a great kick. Its very powerful and versatile. I think people should learn it and use it. However, the Karate / TKD style kick is a great kick as well. It needs to be used differently. But, it has plenty of power and is also very versatile. The best kick to use depends on the situation. Part of the game, is to make sure you are in a situation where you can pick your best weapon. Whats interesting is that guys who train to use the 308, the 50 BMG and the 20 mm cannon, also carry a 9mm. And they know when to use each. Which is better? The M-16 or the 308? What is the situation? What is the range? Both are extremely effective when used in the right situation. Even though the 308 hits much harder than the M-16, the M-16 is still an extremely effective rifle to use in battle. (even the M-16 guys carry a 9mm as well)