I also confused with that because i remember we need to use launcher to finish Tyrant in B scenarios. Otherwise we can not finish the game.

So it was a bit confused if we group knife only for all four scenarios. I also want some tips as well lol.

Knife Only is self explanatory cause the name equals the definition.

Low% is different between games but you could compare the B scenarios with A Link to the Past Low% were you only pick up the things you need to finish the game.

Therefor Knife Only is only possible on A scenarios and Not possible on the B scenarios. 

Rather then name the A's knife only and the B's Low% we could just use Low% for both cause that label actually fits both scenarios.

And I know who it is that keeps changing the names of the subcategory, could you please stop that? Or atleast put forward a argument...

Only reason I'd say Knife Only still makes more sense for both, is that Knife Only is a term inclusive to this community. Regardless of whether or not a rocket is used to kill the tyrant, when people say 'Knife Only', we know what it means. 

Same in RE1 (Rocket), RE2 (Rocket), RE3 (Railgun), RE CVX (Linear Launcher).

Low% is a term pulled from games with a end-game %. Which makes no sense in the context of RE because RE games don't end with a %, they end with a time and rank. So whilst you can say "you use a rocket so knife only makes no sense", it could also be said that there's no %, so low% makes no sense.

Any% could argued to be the same problem, though Any% is arguably the most common term in speedrunning. Everyone knows (or should know) by this point 'any%' is a term that simply means "as fast as possible". Its meaning changed a long time ago. A lot of games have opted more for 'New Game' rather than Any% though, to try and stray away from using it.

TLDR; In the context of RE, low% means nothing whatsoever. Whereas Knife Only is a term that is (probably) one of the most common or recognizable. It's only a name at the end of the day though, and the most important aspect I guess is that everyone, even those not fully familiar, understand what it means in the context of the game in question.

@UKViixen best tip that i can give you is be patient and don't take too much damage before the bosses, the lines of the game are the same until the boss fights, for lickers if you have difficulties better thing is making them jump instead of dodging, about the fights:

A scenarios

**G-Mutant**
Works the same as Any% fight, just try attack his left arm and you'll be OK, don't let any mini enemies alive 'cuz the autoaim is so stupid that finds the worst enemy. (I do 3 steps and 2 slash, then i go back and start slashing his left arm)

**Alligator**
I learned this fight taking intentional damage at least twice before he starts his 1st run, after that run slash him from right to left or the opposite, never front to front 'cuz his hitbox is focused in his at the beginning of the jaw. When he prepares his 2nd run use the cylinder for canceling his run, with that you'll have more chances for slashing him. He'll run away if you're at the door screen (don't be scared if you think you're not winning, that's the only way for being sure if you made it) and don't try quickshooting :) you can defeat him without using them.

NOTE: If you stun him with one of the slashes that gives you more chances for defeating 'cuz the damage is more.

**G2**

I have 2 ways for managing this fight.

1. Using the manipulation that use Smallvillecs (2:47 is the fight)
https://youtu.be/o7iJKAzzyhQ?t=2m47s

2. My other strat is called "Mercy strat". If your HP is almost in red caution, G2 will prepare his claws for doing a kind of final attack, when he's doing that slash him like 3 times, then walk back few steps and wait him. If he does the same position repeat the process, if not just stay away from him a few more steps until he decides do the position.

**G4**
This is the nightmare, the 1st phase just slash him from his back until he changes his form, keep your health at max. In the 2nd form best tip is you have to be closed to the walls and not too close to him 'cuz he can grabs you, each 4 steps he'll jump (this happens sometimes, 2 or 4 are the steps)

And NEVER slash each enemy to the front, down has more range :)

I'm doing some videos with knife battles and how to manage them. Hopefully i'll have ready before ends this month, i'll post them on guides section, same that i did like RE3 with Nemesis battles.