Darth Sidious (without lightsaber) vs Darth Vader

A few observations about Koth vs Vader. Vader dominated that fight, and Koth was forced to retreat the entire time, similar to Anakin vs Kenobi on Mustafar. Vader had the upper hand for the whole fight. 

Being pushed back means nothing here. 1) He was close to the door, 2) Vader is stronger (no one's disputing that), and 3) Koth is primarily a defensive fighter in canon. He lets his opponents drive him back.

Koth was practically allready done before he was stabed by Vader. Just look at him, he barely stands.

You're seeing what you want to see. Koth is quite clearly ready to continue fighting. And he's not "barely standing":

Also, Koth was noted to become more powerfull than he was as a jedi.

A meaningless claim since Vader had never seen Koth fight before.

The same Koth who as a jedi,, while having a broken arm,

Proof a broken arm hampered him?

was comparable with Grievous in skill.

Already noted this. 

Not to mention that is likely that in this situation Koth fought harder than ever to save his family. 

Largely irrelevant as he'd just be bringing all his skills and powers to bear, same as against Grievous (who he wanted to end for the lives he'd taken).

Massively pre prime Vader>> prime Koth>> jedi Koth> injuried Koth who is a match for Grievous.

If talking power, maybe. Since we're talking skill:

14 BBY Vader ~ 14 BBY Koth (who hadn't picked up a lightsaber for 5 years) ~ TCW Koth ~ Grievous.

@BoD:

Being pushed back means nothing here. 1) He was close to the door, 2) Vader is stronger (no one's disputing that), and 3) Koth is primarily a defensive fighter in canon. He lets his opponents drive him back.

Proof that Koth is a defensive fighter?

You're seeing what you want to see. Koth is quite clearly ready to continue fighting. And he's not "barely standing":

He looks like he is barely standing for me and he is visibly injuried. Feel free to disagree. I don't really think this point will lead anywhere.

A meaningless claim since Vader had never seen Koth fight before.

It is extremly likely that Anakin in his years as a jedi saw Koth fight. Vader wouldn't talk about Koth being more powerfull than he was as a jedi if he didn't know how powerfull he was as a jedi. And Koth didn't disagree. Vader even feels the fear and anger in Koth. As a jedi Koth couldn't use these as it was forbiden, and we know that in Star Wars many characters received power boosts from fear/anger/hatred.

Proof a broken arm hampered him?

Seriously? It's a broken arm. Any kind of injury can hinder a combatant. There is no need for a quote to see this. We argue for characters to be hindered by all kind of insignificant things, but you need a quote for this?

Largely irrelevant as he'd just be bringing all his skills and powers to bear, same as against Grievous (who he wanted to end for the lives he'd taken).

In Star Wars, emotions are a big factor. An Anakin that will fight for Padme's life will be stronger than Anakin in a normal fight. This is a trope you can see everywhere in Star Wars (and most other fictional universes) It is likely that Koth received am amp here due to fighting for his family similar to Kanan's amp against the GI or Kenobi against the brothers after Gallia's death. This is also suported by the dialog "now i have something to lose" (he said this as a reason why he is more powerfull than ever). The text couldn't be more clear.

If talking power, maybe. Since we're talking skill:

14 BBY Vader ~ 14 BBY Koth (who hadn't picked up a lightsaber for 5 years) ~ TCW Koth ~ Grievous.

Are you sure this comic takes place in 14 BBY? And proof for Koth not using a lightsaber in 5 years? Anyway, Kenobi didn't used one for a longer period of time and was fine (in canon at least)

Haven't seen any evidence or even an argument for Sheevy so far

Sidious ragdolls.

Sidious without lightsaber doesn't get worse fighting (remember the duel with Yoda).