Then, you think that cutting Hirudegarn's tail made him weaker than SS3 Gotenks for SS3 Goku to be able to fight him?
That's what I think. But at the very least, we know that destroying his tail was a grevious injury, as the tail seemed to be an important part of his biology, and he vomited blood when it was cut off. Injuries make you weaker.
And Ryuken is so powerful that would make Goku looks (suppose) 10 times stronger than he actually is?
Yes. Did you see what it did in GT?
They never said Hirudegarn lost power, it should be something worth noting if the difference between their powers was so drastic.
Like when everyone noted that SS Gohan's ki didn't actually disappear after Cell hit him? That such a ki didn't go from "stronger than SS Goku" to "zero"?
But they detected his weakness when he attacks, which is actually the main point of defeating Hirudegarn. Ryuken most likely consists in concentrating all of Goku's battle power in his fist, like he did against Piccolo Daimaou when we see the image of an Oozaru instead of a Golden Dragon.
Nope. We see that this attack allows him to hit FAR outside of his own weight class. Not only here, but in GT too.
Goku beat Majin Boo with a Super Genkidama, why use this as an example, really? By the way, SS3 Goku couldn't beat Pure Boo in an one-on-one match, besides previous statements suggesting otherwise.
I'm using it because it's an absolutely perfect example of the logic you're trying to use. SS3 Goku did beat Hildegarn, sure, but he used a super haxxed technique to do it, and couldn't defeat him normally. It's no different than SS Goku using a super powerful technique to defeat Pure Buu.
I'm afraid this may end up in a Goku vs Gohan & Gotenks debate, I really don't want to make the discussion to take that direction, my apologizes, but I don't like to see people tossing around manga establishs that Goku is weaker than Gotenks & Gohan as if it were a fact, even when they have good evidences to back their opinions up
Yeah, no compromise here. Gohan and Gotenks are stronger than Goku, that's a fact, it's stated over a dozen times and never contradicted, anyone who says otherwise is being willingly blind or has been mislead from only seeing the self-contradictory anime.
. Personally, I believe the statements are very clear to build up the idea of the new generation being stronger than the previous, as far as to put a good end to every strenght debate. However, as well noted posts above, Boo Arc's conclusion had a plot twist transferring the spotlight from Gohan to Goku, I risk in the moment Evil Boo didn't change to Pure Evil Boo, but instead to Kid Boo, or even when Evil Boo absorbed Gotenks.
What does that have to do with anything?
I would say it is even embarassing to admit SS3 Goku looks the strongest Z-Fighter after living about 10 years thinking otherwise. This 13th movie is a perfect example that Goku's strenght is not that consistent.
No, it's a perfect example that Toei gives zero shits about consistency. Not that we didn't already know that. The manga is VERY consistent about where Goku stands.
Even the guidebooks care not to mention SS3 Goku or Goku in general when the strenght comparisons aren't as obvious as possible.
Why should they? The manga itself already did! Why would a guidebook need to state, for example, post-zenkai Vegeta is stronger than Cui?
Also, some books do talk about Goku compared to Gohan and Gotenks. Albeit indirectly. All of the comparisons favor Gohan and Gotenks.
What is the problem with accepting the statement as a fact? It just points out that Hirudegarn is the second strongest villain, because Janenba could beat Goku, while himself was at most Goku's level by saying they "traded blows evenly By "poorly described", I mean I would give a description like "The phantom majin that gave a hard time to the Z-Fighters, but was at last defeated by Goku's new technique, the Ryuken! Since he fought evenly with SS3 Goku, the same that was beat back by Janenba, strenght-wise he is the No.2 movie villain." Well, I don't think it can be more specific than that, I apreciate any help.
Because they never traded blows evenly. The line is referencing something that
didn't happen. It's like saying that Cooler is stronger than everyone up to that point because "he traded blows evenly with Super Saiyan Goku". It also is not considering anything into the equation other than "Hildegarn lost to Goku, Janemba beat him, Janemba > Hildegarn". It'd be like if a guidebook came out and said this:
"The pure Majin Buu is a formidable opponent capable of trading blows evenly with even Super Saiyan 3 Goku, but since No. 19 from the previous storyline could beat back Super Saiyan Goku, who defeated Majin Buu, strength-wise this makes him No.2 out of Goku's opponents."
I just noted you've used these examples as a way to disregard whatever is "official" called that don't fit in your standards. Sorry if I interpreted it wrong. I mean, discussing the battle power's numbers by themselves, they don't exactly suggest what you've said or do you think [Boo Arc] SS Goku's true power should be only at 3.000 kiri? Even in an in-universe perspective it would be incoherent, since Base Goku should be close to Yakon, who was at 800 kiri. Of course, this is a theory of mine.
Wait, what? I'm simply saying that the 'official' material said SS Goku in the Buu arc has a battle power equal to himself in the Freeza arc, which obviously isn't true.
Now I understand, you mean the events that did not happen is the "trading blows" thing.

However, what would sound better than "traded blows evenly"? Something like "fought evenly"? I guess this is the point.
No, that wouldn't be any better, because they didn't fight evenly. Again, Hildegarn just beat on Goku, then Goku used his a special technique and one-shotted Hildegarn.